Colon Cancer

What Is Colon Cancer?

Colon cancer is a common type of malignancy (cancer) in which there is uncontrolled growth of the cells that line the inside of the colon or rectum. Colon cancer is also called colorectal cancer.

  • The colon, also known as the large intestine, is the last part of the digestive tract.
  • The rectum is the very end of the large intestine that opens at the anus.

Understanding Cancer

The body is made up of different types of cells that normally divide and multiply in an orderly way. These new cells replace older cells. This process of cell birth and renewal occurs constantly in the body.

Cancer or malignant growths occur when:

  • Some cells in the body begin to multiply in an uncontrolled manner.
  • The body’s natural defenses, such as certain parts of the immune system, cannot stop uncontrolled cell division.
  • These abnormal cells become greater and greater in number.
  • In some types of cancer, including colon cancer, the uncontrolled cell growth forms a mass, also called a tumor.

Some tumors are benign, which means that they are not cancerous. Cancerous or malignant tumors grow out of control and can invade, replace, and destroy normal cells near the tumor. In some cases, cancer cells spread to other areas of the body.

There are two kinds of growths that occur in the colon:

  • noncancerous growths, such as polyps.
  • Malignant or cancerous growths. Colon cancer usually begins with the growth of benign growths such as polyps.

Most types of colorectal cancer are adenocarcinomas. This means that the cancer cells are formed from abnormal gland cells that line the inner surface of an organ. The prefix “adeno” means “gland.” In colorectal cancer, the abnormal growth begins to form in the inner lining of the large bowel.

Nice To Know:

Other forms of colon cancer may occur, but are not nearly as common as adenocarcinomas.

  • Tumors that begin in connective tissue, such as sarcomas
  • Tumors that begin in the lymphatic system, such lymphomas
  • Rare cancers such as carcinoids and gastrointestinal stromal tumors.

If a polyp develops and is not removed, it may become cancerous. Once a cancer develops it begins to invade the intestinal wall and may spread to nearby lymph nodes. Lymph nodes are part of the lymphatic system, which carries special filtered fluids throughout the body. Through the lymphatic system, cancer cells may also be carried to areas of the body far away the original tumor.

This process of cancer cells traveling to other parts of the body is known as metastasis. The spread of cancer may also occur via the blood stream. Colon and rectal cancers that metastasize through the blood stream will travel first to the liver. There the cancerous cells may continue to grow and develop new tumors. As these new tumors continue to grow and spread further, the function of vital organs, such as the liver, may deteriorate.

About The Digestive System

The digestive system receives food, breaks it down into smaller, useful nutrients, absorbs these nutrients into the bloodstream, and eliminates the remaining waste from the body.

The digestive system is made up of

  • The esophagus
  • The stomach
  • The small intestine
  • The large intestine, also known as the colon <

The colon has several parts:

  • Ascending colon – Beginning in the lower right abdomen and continuing up the right side.
  • Transverse colon – Beginning at the upper right side of the abdomen and continuing across to the left side of the abdomen.
  • Descending colon – From the left upper abdomen straight down to the left lower side.
  • Sigmoid colon – An S-shaped section that leads downward into the pelvic cavity.
  • Rectum – The last six or so inches of the colon, ending at the anus.

Facts About Colon Cancer

  • About 150,000 new cases of colorectal (colon and rectal) cancer are diagnosed each year in the U.S., making it the second most common type of cancer and the second leading cause of cancer death in the U.S.
  • One-third of all colorectal cancers are found in the rectum; the rest are found in other parts of the colon.
  • Screening for colorectal cancer should begin at the age of 40 in healthy adults. Seventy to 80 percent of colorectal cancer cases occur in adults without specific risk factors.
  • Widespread screening for colorectal cancer could save up to many lives each year.
  • Early detection reduces the probability of major surgery and increases chances of cure.
  • The risk of colon cancer increases after age 40.
  • Both men and women are equally at risk for colorectal cancer.
  • In the U.S. the death rate for colorectal cancer is declining. This may be due to a higher rate of screening for the disease.
  • Colon cancer may affect any racial or ethnic group; however, some studies suggest that Americans of northern European heritage have a higher-than-average risk of colon cancer.


What Causes Colon Cancer?

There are several causes for colorectal cancer as well as factors that place certain individuals at increased risk for the disease. There are known genetic and environmental factors.

People at risk for colorectal cancer:

  • The biggest risk factor is age. Colon cancer is rare in those under 40 years. The rate of colorectal cancer detection begins to increase after age 40. Most colorectal cancer is diagnosed in those over 60 years.
  • Have a mother, father, sister, or brother who developed colorectal cancer or polyps. When more than one family member has had colorectal cancer, the risk to other members may be three-to-four times higher of developing the disease. This higher risk may be due to an inherited gene.
  • Have history of benign growths, such as polyps, that have been surgically removed.
  • Have a prior history of colon or rectal cancer.
  • Have disease or condition linked with increased risk.
  • Have a diet high in fat and low in fiber.

Need To Know:

Who is at risk for inherited forms of colorectal cancer?

  • People whose relatives developed colorectal cancer before age 60.
  • Those with relatives who have other forms of cancer, particularly breast or ovarian cancer.
  • Those with a family history of stomach, abdominal, bowel, bone, or liver cancer. In the past, colorectal cancer was misdiagnosed as stomach, abdominal, or bowel cancer, or, in later stages, the cancer may have spread to the bone or liver.
  • Distant relatives, such as cousins, aunts, uncles, etc., who develop colorectal cancer may raise the risk of colorectal cancer for other distant family members. The relative increase in risk is not as high as in those who have first-degree relatives, such as parents or siblings with colorectal cancer.

Having certain diseases or conditions may place people at increased risk for colorectal cancer. These include

  • Chronic ulcerative colitis, an inflammatory condition of the colon. People in this risk category have long-term disease, most for ten years or more.
  • Crohn’s disease, which is an inflammatory disease of the gastrointestinal tract. This disease may increase colorectal cancer risk, although not as much ulcerative colitis.
  • A history of breast, uterine, or ovarian cancer in women.
  • Inherited a specific colorectal cancer syndrome. Those with an inherited syndromes may develop colorectal cancer at a much younger age, in their 30s or even younger.

Inherited Colon Cancer Syndromes

Inherited colon cancer syndromes is a name given to a group of different types of colon cancer found to be directly inherited, or passed down from one generation to the next. Over the past several years, genetic forms of colon cancer have been identified and genetic tests developed.

Need To Know:

Genetic forms of colon cancer represent a smaller percentage of all colon cancer cases. However, those with a strong family history of colon cancer may consider talking to a genetic counselor. Those at high risk may choose to undergo screening at an earlier age.

There are two basic forms of colon cancers recognized as having a genetic basis:

  • Familial adenomatous polyposis (FAP) is a rare genetic disorder of the colon characterized by the development of hundreds of polyps on the inner walls of the colon. People with FAP are at a higher risk for developing colon cancer at an early age (in their early 30s).

    The treatment of choice is to have an operation to remove the diseased colon to avoid the eventual development of colon cancer. This operation can be done without the need for a colostomy.

  • Hereditary nonpolyposis colon cancer (HNPCC) is a form of colon cancer that runs in certain families. HNPCC is divided into two types:
    • Type I: People with this form of HNPCC can develop colon cancer before age 50.
    • Type II: People with this disorder are not only at higher risk for colon cancer before age 50 but are also at high risk for uterine, ovarian, thyroid, bladder, and other cancers.

Nice To Know:

Reliable blood tests can now determine if a person has certain genes responsible for inherited colon cancer. Inherited colon cancer makes up about 20 percent of colon cancer cases.

Gastrointestinal Carcinoid Tumors

Gastrointestinal carcinoid tumors are a rare form of cancer affecting the intestinal tract, including the stomach, small intestine, appendix, colon, or rectum. Carcinoid tumors do not usually cause major, recognizable symptoms and can take years to develop. In most cases, these tumors are accidentally discovered during abdominal surgery. These tumors secrete hormones – groups of chemicals released into the bloodstream that have an effect elsewhere in the body.

In some people, carcinoid tumors may cause symptoms known as “carcinoid syndrome”:

  • Facial swelling with redness or flushing
  • Wheezing
  • Diarrhea

Carcinoid syndrome symptoms usually occur only if the cancer spreads to the liver.

Treatment for carcinoid syndrome depends on the stage of the disease and the person’s overall health. Treatment may include surgery,radiation therapy, or chemotherapy.

What Are The Symptoms Of Colon Cancer?

The symptoms of colon cancer can be confused with those of a number of digestive disorders. Having one or more of these symptoms does not mean you have cancer. In all cases, people with the following symptoms should contact their doctor:

  • Bleeding from the rectum. Sometimes blood can be seen on the toilet tissue or in the toilet bowl after a bowel movement. Other things can cause rectal bleeding other than cancer, but rectal bleeding should never be ignored.
  • Changes in bowel habits. These are not usually caused by cancer; however, be sure to discuss such changes with a doctor. If diarrhea or constipation lasts for more than two weeks or bowel habits go back and forth between diarrhea and constipation, or if the stool is unusually narrow, consultation should be made with a doctor.
  • Pain in the abdomen or rectum. Discomfort or dull, vague, or sharp pain in the abdomen or rectum may have a number of possible causes. It does not mean that cancer is present but you should make an appointment with your physician.
  • A feeling that a bowel movement cannot be completed.
  • Unexplained weight loss, unusually low red blood cell counts or anemia, paleness, fatigue, or a yellowish coloring of the skin or whites of the eyes.

Need To Know:

There are many common causes for bleeding from the rectum such as:

  • Hemorrhoids may produce bright red blood from the anus.
  • Diverticulosis, in which tiny “pockets” in the wall of the intestine can form and bleed when inflamed or irritated.

Always get checked by a doctor to determine the cause of rectal bleeding and to obtain treatment for the underlying cause of bleeding.


What Screening Tests Are Available For Colon Cancer?

Screening for colorectal cancer involves special tests performed on people who have no symptoms of a particular illness.

Good screening tests are:

  • Safe
  • Relatively inexpensive
  • Proven effective in detecting the disease at an early stage and reducing the death rate from that disease

Current screening tests for colorectal cancer meet these four requirements and include:

Digital Rectal Exam

During a digital rectal examination (DRE) the doctor inserts a gloved, lubricated finger into the rectum to check for abnormalities. This is a routine part of a physical examination and commonly used to screen for colorectal cancer.

This test is effective in detecting rectal cancer; however, doctors are able to detect only 7 to 10 percent of colorectal cancers since most of the colon cannot be felt by the examiner’s finger. The goal of colorectal cancer screening is to detect the cancer before it grows large enough to be felt during such an exam.

By itself, the digital rectal exam is not considered an ideal screening test for colorectal cancer, but rather is used along with other screening tests.

Fecal Occult Blood Test (FOBT)

The fecal occult blood test (FOBT), also called the stool blood test or the guaiac test, is used to detect tiny amounts of blood in a stool sample. This test detects small amounts of blood in the stool that would not be visible.

Stool samples are smeared onto special cards and dropped off at the doctor’s office or a laboratory. This is done because tumors may bleed on one day and not the next; therefore, blood may be present in stool on one day and not the next. When colorectal cancer is present, the blood may be dark, or mixed with stool, but you often can’t see it. For this reason, the FOBT is important.

Need To Know:

Blood in the stool does not always mean you have colorectal cancer. Other causes include:

  • Bleeding ulcers
  • Inflammation of the stomach or gastritis
  • Inflammatory bowel disease (IBD)
  • Hemorrhoids

If fecal blood is found, additional tests are done to rule out cancer. Cancer can still be present if the FOBT is negative. This can happen if there was no bleeding when the test was performed. The results may come back negative but cancer is present. This is known as a false negative test.

Flexible Sigmoidoscopy Procedure

During a sigmoidoscopy procedure the doctor inserts a soft flexible, fiberoptic scope into the anus. The walls of the rectum and sigmoid portion of the colon are checked for tumors. A flexible sigmoidoscopy procedure may detect:

  • About half of all colon tumors
  • Nearly all rectal tumors

If doctors discover a growth or tumor during this procedure, abiopsy will be performed. During a biopsy, a small tissue sample is removed and then prepared for examination under a microscope. The biopsy procedure does not hurt.


A colonoscopy is similar to a sigmoidoscopy but is a more thorough examination of the entire colon. Patients receive medications that help them relax during the procedure. A flexible scope with a tiny camera attached is gently guided from the anus through the colon. Looking at the images provided by the camera on a monitor, the doctor examines the inside of the colon for any signs of inflammation, disease, or polyps. During the procedure, the doctor can take a sample of any suspicious areas for further testing, and can remove any polyps that are discovered.

How-To Information:

Colon Cancer Screening Guidelines

Seventy to 80 percent of all colon cancers occur in adults without known risk factors. The American Cancer Society guidelines recommend adults should begin colon cancer screening by age 50 years, either with:

  • Annual stool occult blood stool tests, sigmoidoscopy, and digital rectal exam every five years, or
  • Colonoscopy and digital rectal exam every 10 years, or
  • Double-contrast barium enema and DRE every five to 10 years.

Some experts recommend beginning blood stool tests and a digital rectal exam at age 40. For those who undergo periodic evaluation of the entire colon, no annual FOBT is needed.

Those at higher-than-average risk for colon cancer should consult their doctor to begin screening at an earlier age. Their doctors will probably recommend more thorough screening tests, including a colonoscopy or barium enema rather than sigmoidoscopy.

People are considered at higher-than-average risk if they have

  • Had colon polyps removed
  • Relatives who developed the disease
  • Inherited colon cancer syndrome
  • A family history of this syndrome


How Is Colon Cancer Diagnosed?

If people experience symptoms like those of colorectal cancer, they need to make an appointment with their family physician, a gastroenterologist, a physician specially trained in the management of digestive system disorders, or a colon and rectal surgeon, a specialist in treatment of diseases of the colon.

The doctor performs a thorough clinical evaluation that includes:

  • A complete medical, family, and drug history
  • A physical examination, including a digital rectal examination

Tests that may be performed include:


A sigmoidoscopy is a specialized screening or diagnostic test for colorectal cancer. People age 50 and older who have no symptoms may have a sigmoidoscopy to check for suspicious areas inside the colon. Those who have symptoms, such as abdominal discomfort, persistent diarrhea, or blood in the stools, have this test to help determine the exact cause of these problems.

During this test:

  • A flexible viewing tube known as a sigmoidoscope is inserted through the anus and rectum and on through the lower part of the colon, called the sigmoid. A sigmoidoscope is a soft, flexible fiberoptic scope.
  • Doctors examine the inner walls of these areas to determine if disease is present. They look for tumors, polyps, inflammation, and other tissue changes that are associated with diseases of the anus, rectum, and sigmoid colon.
  • If doctors see an area of tissue in the colon that looks unusual or questionable, they remove a small sample of tissue, known as a biopsy.

The tissue sample is sent to a laboratory for analysis. A pathologist examines the biopsy tissue under a microscope. If the tissue is abnormal or appears normal but suspicious, the patient is scheduled for a colonoscopy.

A sigmoidoscopy may detect about 50 percent of colon tumors and nearly 100 percent of rectal tumors.

The benefits of a sigmoidoscopy include:

  • A direct view of the inner walls of the rectum and sigmoid colon
  • Ability to obtain a biopsy sample
  • Test is performed in the doctor’s office without the need for sedatives
  • There may be a sense of discomfort but usually no pain.


A colonoscopy is a screening and diagnostic procedure during which the inside walls of the entire colon are examined. The doctor uses an instrument called a colonoscope. This is a flexible fiber optic tube that bends around with the shape and turns of the colon. The colonoscope is typically attached to a video camera and monitor. This allows the doctor to clearly view the inside walls and lining of the colon.

A colonoscopy is used to diagnose conditions of the bowel, including:

  • Ulcerative colitis
  • Crohn’s disease
  • Diverticular disease such as diverticulosis
  • Polyps
  • Colon cancer

How-To Information:

When preparing to have a colonoscopy:

  • Do not eat on the day of the test.
  • Drink only clear liquids on the day before the test.
  • A special laxative is given the day before the test in order to cleanse the intestines.
  • An enema may be prescribed for the day of the test.

Antibiotics may be prescribed for people who have:

  • An artificial heart valve
  • Undergone joint replacement surgery
  • Taken preventive antibiotics before dental work.

Antibiotics help reduce the relatively small risk of infection associated with artificial components in the body.

Other Tips:

  • Don’t take anti-inflammatory drugs, such as aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen sodium for at least 10 days before the test. This helps minimize the possibility of excessive bleeding.
  • Arrange for a ride home after the colonoscopy.

During a colonoscopy,

  • The patient lies on his or her left side.
  • The doctor administers a sedative intravenously, to help the patient relax and not feel any discomfort.
  • After a rectal examination and lubrication of the anal area, the colonoscope is gently passed into the rectum and is slowly advanced along the colon.
  • A small amount of air is inserted into the colon to help keep the walls apart. The air fills the interior space of the colon and allows the instrument to move freely inside the colon.

If the doctors see polyps in the colon, it may be possible to remove them. Samples from the polyps are removed and sent to a laboratory for thorough examination.

A colonoscopy is similar to a sigmoidoscopy, but it is more extensive and may be preferred in some patients. Because polyps are sometimes removed during a colonoscopy, the procedure is diagnostic as well as therapeutic.

Need To Know:

Colonoscopy is a safe procedure, but it is not risk-free. On rare occasions, complications may occur, including

  • Infection
  • Bleeding
  • Accidental puncture or perforation in the area where the colonoscope passes

After the procedure, the doctor should be called immediately if the patient:

  • Does not feel well
  • Experiences excessive bleeding from the rectum
  • Has severe abdominal pain
  • Eliminates black stools; this may indicate the presence of bleeding
  • Develops a fever

Double Contrast Barium Enema (Barium Meal And Enema)

The double contrast barium enema, also called air contrast barium enema, is a special test that helps doctors diagnose diseases of the colon. Barium is a chemical substance that shows up on x-ray films. This allows doctors to see an outline of the colon on x-ray films.

During this test:

  • The bowel must be as empty as possible. The evening before the test, the patient takes a laxative. Liquid barium is inserted into the rectum through a small tube.
  • Numerous X-ray pictures of the intestine are taken and provide the radiologist a clear, outlined view of the entire colon.
  • A radiologist carefully examines the X-ray films and reports on any abnormalities.

What Is Colon Cancer Staging?

Staging is a method to describe how advanced a cancer is. Staging for colorectal cancer takes into account the depth of invasion into the colon wall, and spread to lymph nodes and other organs:

  • Stage 0 (Carcinoma in Situ): Stage 0 cancer is also called carcinoma in situ. This is a precancerous condition, usually found in a polyp.
  • Stage I: The cancer has spread through the innermost lining of the colon to the second and third layers of the colon wall. It has not spread outside the colon.
  • Stage II: The cancer has spread outside the colon to nearby tissues.
  • Stage III: Cancer has spread to nearby lymph nodes, but not to other parts of the body.
  • Stage IV: Cancer has spread to other parts of the body, such as the liver or lungs.

Colon cancer is “staged” according to the pathological findings (results from biopsy) after surgery. Staging may include findings from imaging studies, such as chest x-ray, CT scan, a computer-assisted diagnostic procedure that produces cross sectional images of the body, MRI, PET scan, and endorectal ultrasound. Not all of these tests are needed in every person.

Staging helps the doctor to:

  • Forecast how an individual may do over time
  • Estimate the risk of recurrence
  • Develop an individualized treatment plan for a patient

Depending on the stage of the cancer, the doctor can recommend surgery alone or in combination with radiation and chemotherapy. The approach to treatment is individualized to each person and the stage of their disease.

Endorectal Ultrasound

Endorectal ultrasound (ERUS) may be performed in a person with rectal cancer. In an ultrasound test, sound waves bounce off the part of the body to be examined and produce images of the area. These images are then displayed on a screen or monitor and saved for evaluation.

During an ERUS test, a probe is inserted into the rectum through the anus. The doctor then determines the depth of invasion of the cancer through the wall of the rectum and checks to see if the cancer has spread to lymph nodes or to organs adjacent to the rectum.

ERUS testing helps to stage the cancer prior to surgery. This way optimal therapy may be individualized for each patient. For example, if the ERUS determines that the cancer has penetrated completely through the rectal wall, the surgeon may request that treatment with radiation be given prior to surgery in order to shrink the tumor.

How Is Colon Cancer Treated?

The outlook for people with colon cancer has improved steadily in recent years. Three types of treatment are available for individuals with colon cancer:

  • Surgery is an operation that involves removing the cancerous section of the colon. This is the primary treatment for colon cancer for most individuals.
  • Chemotherapy involves treatment with drugs that destroy fast-growing cells, like cancer cells. This treatment is given to persons with advanced cancers that have spread outside of the colon.
  • Radiation therapy is a specialized treatment using radiation to destroy rapidly growing cancer cells. This is usually reserved for treatment of rectal cancer and may be given before surgery, often in combination with chemotherapy. This treatment may shrink the tumor and improve the chances of avoiding a permanent colostomy in select persons.

When detected early, surgery alone is the only treatment necessary, and cure rates are excellent. Sometimes, even when the cancer is surgically removed, radiation therapy or chemotherapy may reduce the risk of cancer spread.

How Is Surgery for Colon Cancer Performed?

The goal of surgery for colorectal cancer is to eliminate the cancer or, in the case of advanced disease, relieve symptoms.

  • With the exception of some less serious operations performed through the anus, surgery for colorectal cancer is a major operative procedure.
  • Some very early, small colorectal cancers may be removed with a colonoscope.
  • In most cases, a major operation is required and a length of the intestine is removed. But even when a large part of the intestine is removed, most people function as well as they did before the surgery.

Nice To Know:

The human body contains about 20 feet of small intestine and five feet of large intestine. Therefore, normal digestive functions are possible even if a portion of the small intestine or large intestine is removed. Most digestion of food actually occurs before the food reaches the colon.

The purpose of surgery for colorectal cancer is to achieve long-term remission. The goal is to:

  • Remove the primary cancer.
  • Leave an area around the cancerous site that is free of cancer cells. Therefore, no cancer cells are present in the tissue surrounding the surgery site.
  • Remove nearby lymph nodes. The nodes are then examined to see if they contain any cancer cells. This is important to correctly stage the cancer.

Types of colorectal cancer surgery, from the least to the most extensive surgery, are:

Colonoscopic Excision Of Early Colon Cancers

One important advance in the management of colorectal cancer over the past 30 years is the development of the colonoscope. This specialized instrument provides an accurate method for examining the colon. A colonoscope is also an important method of treatment of polyps through excision.


It is possible to remove small cancers, small benign adenomas or polyps with a colonoscope. This is called a polypectomy. General anesthesia is not required. This procedure is performed on an outpatient basis.

Need To Know:

Screening tests are important. When detected early, a greater number of tumors may be removed with a colonoscope. Since this type of surgery is not as serious and involved, recovery time is shorter than with major surgery.

Local Excision For Rectal Cancer

Small superficial rectal cancers are sometimes removed by a less invasive operation than a bowel resection. The surgeon, operating through the anus, removes a disk of tissue containing the tumo. The pathologist evaluates the tissue carefully to determine the depth of invasion.

Bowel Resection And Anastomosis

This procedure involves:

  • Opening the abdomen
  • Locating the diseased area
  • Making sure it is carefully removed
  • Joining the bowel ends together with stitches
  • Closing the abdomen

During bowel resection, the surgeon removes the diseased portion of the bowel. Some tissue surrounding the diseased portion of the bowel is also removed to help make sure all the cancerous tissue is removed. Then the surgeon joins the two ends of the bowel together again, a process known as anastomosis.

Sometimes, a temporary colostomy may be performed, especially in those with rectal cancer. The surgeon may choose to create a temporary colostomy located above the anastomosis. After about three months, if tests show that the anastomosis is healed, then the colostomy opening is closed.

Abdominoperineal Resection

Abdominoperineal rection is an operation during which the entire rectum and anal canal are removed. This operation is performed when it is not possible or advisable to preserve the anal sphincter muscles or to do a local excision. With recent advances in treatment most patients do not require such radical surgery.

Abdominoperineal refers to the fact that a “double approach” is required to remove the tumor.


During a colostomy:

  • The doctor makes an opening in the skin to the left or right of the belly button. This opening is known as a stoma.
  • The surgeon then brings the end of the intestine through the opening and stitches it to the surface of the skin.
  • Waste materials pass through the stoma and empty into a small bag called a colostomy bag. This bag is fastened to the skin around the stoma. Colostomy bags are worn under the clothing and are not visible to others. They generally do not hamper normal activities.

This is an effective method for the temporary collection and disposal of waste material from the intestines.

Need To Know:

People fear that if they have colorectal cancer, they may need to permanently wear a colostomy bag. Because of improvements in surgical techniques for reconnecting the colon, a colostomy bag is often not needed in the treatment of most colorectal cancers.

Preparing For Colon Cancer Surgery

About a week before surgery, the doctor

  • Discusses with the patient any medications (prescription drugs as well as over-the-counter drugs) the patient normally takes.
  • Advises which medications that interfere with blood clotting must be discontinued. This includes the prescription drug Coumadin as well as over-the-counter anti-inflammatory drugs such as aspirin or ibuprofen.
  • If other medications are taken on a daily basis, the doctor will advise if these should be taken on the day of the surgery.

How-To Information:

Preparing for surgery

  • Patients are usually admitted to the hospital the day before surgery.
  • Don’t eat or drink anything, not even water, at least the eight hours before surgery.
  • The evening before surgery, the bowel is cleansed using laxatives or an enema.
  • You will undergo a physical examination to check on your overall health. This includes blood tests, an electrocardiogram or EKG, urine tests, and chest x-rays.
  • An anesthesiologist visits to discuss the type of anesthetic that will be administered during surgery. Most patients receive general anesthesia so they “sleep” through the surgery.

Recovering From Surgery

The amount of time that people are hospitalized after colon surgery varies. Most people stay in the hospital several days after surgery.

During this time:

  • The intestines are inactive for several days.
  • No food is given by mouth for four to five days.
  • Intravenous infusions provide fluids to prevent dehydration or excessive fluid loss.
  • Pain medication is delivered through an intravenous line or by pump that patients control themselves, providing relief from post-operative discomfort.
  • Once the intestines resume their normal function liquid food is given for the first few days.

How-To Information

The recovery time from colon surgery ranges from tone to two months. During the recovery period, patients should

  • Avoid lifting heavy objects. Such strain may cause a herniation or a rip in the weakened muscles lining the abdominal wall. A gradually progressive exercise program, prescribed by your doctor, helps strengthen abdominal muscles.
  • Follow a high-fiber diet.
  • If excessive gas, diarrhea, or constipation becomes a problem, eliminate the suspected offending food from the diet. It may be possible to reintroduce this food later.
  • If diarrhea is a problem, eat applesauce, bananas, or rice.
  • Take laxatives or anti-diarrhea medications only when prescribed by the doctor.
  • If surgery included a colostomy, instructions on care of the colostomy will be given by specialized nurses called enterostomal therapists.

Need To Know:

Depending on the extent and stage of the cancer, additional therapies, such as radiation or chemotherapy, may be recommended after the patient has recovered from surgery. These therapies are used to destroy any remaining cancer cells. Therapies used after surgery are called adjuvant therapy.

  • If the tumor was removed at an early stage, additional therapy may not be necessary. Surgery alone can achieve long-term remission from colon cancer.
  • If the doctor suspects that cancer cells remain in the body, additional therapies are considered.
  • If lymph nodes contain cancer cells, chemotherapy, with or without radiation therapy, is usually recommended.
  • When colon cancer spreads to other areas of the body, these therapies slow the progress of the disease.

Chemotherapy and radiation may be used alone, together or in conjunction with surgery. This depends on the location of the cancer and extent of cancer spread.

  • Radiation therapy reduces the risk of the tumor recurring in the same spot.
  • Because chemotherapy affects all cells in the body, it is used to kill cancer cells both in the same spot as well as any that may have spread.
  • When radiation therapy is combined with chemotherapy, radiation therapy enhances the effects of cancer-killing drugs.


What If I Need Chemotherapy?

Chemotherapy is the planned, periodic administration of a special drug or a combination of drugs that destroy cancer cells. Chemotherapy may be given:

  • Orally, in pill form
  • By intravenous (IV) infusion, meaning by direct injection into a vein. The drug enters the bloodstream rapidly and circulates throughout the body.
  • Through a catheter or thin tube is inserted into a vein. The drug enters the bloodstream constantly over a period of days or weeks.

Nice To Know:

Chemotherapy is called a “systemic treatment.” The drug enters the bloodstream and travels throughout the body. In this way, chemotherapy destroys cancer cells that have traveled outside of the colon.

Chemotherapy destroys rapidly dividing cancer cells but also damages some healthy cells, including:

  • the roots of the hair
  • the lining of the intestine
  • bone marrow

There may be some temporary hair loss, which is usually not as severe is in chemotherapy for other forms of cancer. There may also be digestive upset and discomfort as well as a feeling of great fatigue.

Nice To Know:

Researchers are constantly trying to find new types of drugs that destroy cancer cells while leaving other healthy cells alone. These will improve or ease the side effects of chemotherapy caused by the destruction of healthy, rapidly growing cells.


What If I Need Radiation Therapy?

Radiation therapy is a treatment option for colon cancer. This form of therapy involves the use of x-rays or other high-energy rays to shrink tumors by destroying cancer cells.

  • Because colon cancer sometimes recurs at its original site, radiation therapy may used to decrease the chances of cancer recurrence. Radiation treatments may be used prior to colon cancer surgery to decrease the size of the tumor, or may begin shortly after the surgery. Radiation therapy is used for colon cancers that have spread beyond the wall of the rectum. This can be determined prior to surgery by testing with endorectal ultrasound and computed tomography.

Radiation therapy may be delivered in two ways:

  • By a special machine in the hospital or doctor’s office. X-rays coming from this equipment are aimed and targeted to a specific portion of the colon.
  • By “planting seeds” of radiation directly into the body through thin plastic tubes.

Need To Know:

Radiation therapy destroys cancer cells but can also damage normal cells.

  • Skin around the treated area may be red and sore.
  • Some people feel tired during the course of radiation therapy.
  • Digestive distress and discomfort may also occur.

In most people, the side effects of radiation and chemotherapy begin to disappear as soon as treatment is finished.

How-To Information:

While undergoing chemotherapy or radiation treatment:

  • Try to eat a variety of foods, with special attention to protein. This helps the body repair the tissues damaged during treatment.
  • If diarrhea is a problem, try avoiding dairy products, which may make it worse.
  • An appetite for large meals may be gone. Try several smaller meals each day.
  • When away from home, carry food and water.
  • Indulge with favorite foods. Taste buds may be temporarily affected by the treatment and foods you once liked may no longer be appealing.
  • Avoid foods high in fat. These foods can cause a sense of “fullness,” without providing enough nutrients.

For more detailed information about radiation, go to Radiation Therapy.

Can Colon Cancer Come Back After Treatment?

When people with colon cancer are treated early, they may achieve full long-term remission. People who have experienced colon cancer – even if their prognosis is good – may worry excessively that the disease will come back or recur. Cancer of the colon may recur at or near the original site.

Those who have had colon cancer are slightly more likely to develop other cancers. Therefore, regular follow-up by a doctor is important to detect cancer that has recurred or any new cancers early. This increases the changes of a long-term remission.

How-To Information:

People treated for colon cancer need to follow a schedule of ongoing testing for the presence of tumor regrowth or the appearance of a new tumor. Such a follow-up regimen may include:

  • A annual stool blood test
  • Sigmoidoscopy or colonoscopy at regular intervals, depending on the individual
  • CEA tumor marker test, or CEA test, which measures the level of carcinoembryonic antigen in the bloodstream.

What is the CEA Marker Test?

CEA may be present in higher than normal levels in the blood of those with colon and rectal cancer and may indicate if cancer has recurred.

  • The results of a CEA tumor marker test are not 100% conclusive because CEA values are not elevated in all people with colon cancer.
  • An abnormally high level of CEA protein is sometimes found in people who do not have cancer, including those with non-cancerous growths.
  • The CEA test does not tell if cancer is present, but rather signals the need for additional diagnostic tests.
  • Researchers are investigating new tumor marker tests for use in people with colon cancer.

Need To Know:

After treatment for colon cancer:

  • Schedule follow-up appointments with your doctor.
  • Ask the doctor any questions regarding treatment.
  • Discuss fears and concerns with the doctor or other healthcare professional. Mention any symptom that is worrisome. After treatment, there may be new symptoms, most of which are not serious.

Consider finding a support group. Many people find it helpful to talk to others who were also treated for colon cancer.


How Can Colon Cancer Be Prevented?

There are several techniques, including screening tests and lifestyle changes, associated with the prevention of colorectal cancer. The best way to help prevent colorectal cancer is to:

  • Schedule regular colorectal cancer screening tests with your doctor. In this way, small polyps may be discovered before they become cancerous.
  • Avoid diets high in fat, alcohol, protein, calories, and red and white meat. Colon cancer is more common in the U.S. and other Western countries where people eat foods high in saturated fat and low in fiber.
  • The use of nonsteroidal anti-inflammatory medications (such as aspirin) may decrease the risk of colon cancer.
  • Eat foods rich in fiber. Dietary fiber is thought to protect against colon cancer because fiber-rich food is digested faster. Therefore undigested food remains in the colon for a shorter period of time.

For further information about fiber, go to Fiber: Its Importance In Your Diet.

Fiber-Rich Foods

Many foods contain high levels of fiber. These include:




  • Oats
  • Oat bran
  • Rye crisp crackers
  • Popcorn
  • Toasted wheat germ
  • Granola
  • High fiber bread
  • Beans
  • Asparagus
  • Beets
  • Broccoli
  • Carrots
  • Kale
  • Corn
  • Okra
  • Potatoes (with skin)
  • Zucchini
  • Apples
  • Figs
  • Peaches
  • Pears
  • Prunes
  • Raspberries
  • Strawberries

Need To Know:

Other important steps toward prevention are:

  • Quit smoking. There is evidence that smoking increases the risk of colon cancer.
  • Drink alcohol in moderation. Some studies suggest that consuming large amounts of alcohol raises colon cancer risk.
  • Get moving. A sedentary lifestyle may increase the risk of colon cancer.


Frequently Asked Questions: Colon Cancer

Here are some frequently asked questions related to colorectal cancer.

Q: Why isn’t everyone screened for cancer?

A: Screening for colorectal cancer is in its early stages. Not all doctors screen for colorectal cancer, or some patients may be reluctant to go for testing. This is unfortunate because widespread screening could save up to 30,000 lives each year. Colon cancer is the second leading cause of cancer death in the U.S.

Q: Do most people who develop colon cancer have risk factors for the disease?

A: Any person is at risk for colon cancer. Most people are in their 60’s and 70’s when diagnosed. Therefore age is a risk factor for this disease. Only one in five have other risk factors for the disease, such as family history of colon cancer.

Q: How can you tell whether stomach distress comes from colon cancer or a less serious disease?

A: Less serious diseases such as irritable bowel syndrome,ulcerative colitis or even the flu may cause digestive symptoms and bowel changes that are similar to those of colon cancer. If you are concerned about bowel or digestive symptoms, seek medical advice as soon as possible. The only way to know if the condition is caused by cancer is to undergo testing.

Q: Don’t hemorrhoids, not colon cancer, cause rectal bleeding usually?

A: True, hemorrhoids are a common cause of rectal bleeding. But a symptom of colon cancer is bright red blood in the stool. So rectal bleeding should not be dismissed as unimportant and should be investigated as to the specific cause.

Q: How does a person’s digestive system function if a large part of the intestine is removed during surgery?

A: The digestive system of most people functions very well after surgery. The small intestine is about 20 feet; the large intestine is about five feet long. People are able to live quite normally without a portion of the small intestine and all of the large intestine. Most digestion takes place before food reaches the colon; therefore, most people function as well as they did before the surgery. The most common change after removal of a portion of the colon is an increased frequency of bowel evacuations.

Q: Do most people who undergo colon cancer surgery have to wear a colostomy bag?

A: No. Recent improvements in surgical techniques have reduced the chances of needing a colostomy bag. And if a colostomy is needed, it is usually not permanent. The procedure may be reversed after the intestines have had the opportunity to recovery from the surgery. In a small number of cases a colostomy may be permanent. But, even in these cases, people become accustomed to a colostomy bag worn inside their clothing for the collection and elimination of waste.

Putting It All Together: Colon Cancer

Here is a summary of the important facts and information related to colorectal cancer.

  • Colon cancer is the second leading cause of cancer death in the U.S.
  • Colon cancer is most easily treated and cured when detected early, before cancer has spread.
  • Age and health history affect who is at risk for developing colon cancer.
  • Symptoms of possible colon cancer include blood in the stool or a change in bowel habits.
  • Routine screening can detect colon cancer early and prevent the development of cancer by removing polyps before they become cancerous.
  • Surgery, chemotherapy, and radiation therapy may be used to treat colon cancer.
  • Treatment is based on many factors and is customized for each patient.
  • Patients should continue to see their doctors regularly after treatment for any signs of recurrence.
  • Support groups can help patients deal with the psychological and social stresses of living with cancer.

Glossary: Colon Cancer

Here are definitions of medical terms related to colon cancer.

Adenocarcinomas: The most common type of bowel tumors. They are usually found in the inner lining of the intestine.

Adenoma: A benign tumor usually made up of gland or gland-like cells. It may crowd out surrounding healthy tissues.

Anastomosis: Surgical reattachment of the two ends of the colon, known also as the bowel, after a portion of the colon is removed by the surgeon.

Anesthesia: In general anesthesia, a drug or combination of drugs used to put the patients “to sleep” during a surgical procedures or operations. In local anesthesia, only a portion of the body’s response to pain is blocked.

Barium Enema: An x-ray procedure during which a special, white chalky liquid is passed into the colon through the anus. This liquid contains barium, a compound that is highly visible on x-rays film allowing the radiologist to see possible abnormalities in the colon.

Barium Meal: A special liquid solution that contains barium, which is highly visible on x-ray film. The patient drinks the solution, waits for a period of time, and then has x-rays taken of the intestines.

Biological therapy: See Immunotherapy.

Biopsy: A relatively small piece of tissue taken from an area of suspicious growth. The tissue is examined under a microscope to determine if cancer cells are present. If they are present, the pathologist performs additional tests on these cancer cells. These tests tell the doctor what type of cancer is present as well as other important factors that help determine the course of treatment.

Bowel resection: Surgical removal of part of the intestines. During this procedure, the diseased portion of the colon is removed and the remaining ends are joined together by the surgeon.

Carcinoid tumors: A rare type of cancer that occurs in the gastrointestinal system. It is usually a slow-growing cancer.

Catheter: A small tube that permits the passage of fluid into a body structure, like a vein, or out of the body, as with a urinary catheter.

CEA tumor marker test: A special blood test that measures the level of a substance in the blood known as carcinoembryonic antigen. This marker is usually higher than normal in people with active colon cancer.

Chemotherapy: The use of special drugs to destroy cancer cells. Chemotherapy is usually given according to a schedule. Usually a period of treatment is followed by a period of “drug vacation.” Then the treatment cycle begins again.

Colon: The major part of the large intestine including the rectum.

Colonoscope: A special instrument used to examine the inner walls of the colon. This long, flexible instrument uses fiberoptics to send images of the colon to a monitor for viewing by the physician.

Colonoscopy: An examination of the inside of the colon with a special instrument known as a colonoscope.

Colostomy: A surgical procedure used in the treatment of colon cancer when the cancer is located low in the rectum. The cancerous tumor and surrounding tissue are removed and a new opening is created in the abdominal wall for the elimination of waste. During this procedure, a section of colon is attached to the abdominal wall to an artificial opening or stoma. Waste material passes through the stoma into a bag.

Crohn’s disease: A chronic inflammatory bowel disease (IBD) characterized by diarrhea, cramping, and loss of appetite with weight loss.

CT scanning: An advanced imaging technique also known also as CAT scanning or computerized axial tomography. During this procedure, a computer-assisted scanner produces cross-sectional images of the body.

Digital rectal exam (DRE): An examination during which a doctor inserts a lubricated, gloved finger into the rectum to check the area for masses or other abnormalities, such as enlargement of the prostate in men.

Diverticulosis: A condition of the bowel in which abnormal pockets form on the inner wall of the colon. These pockets are frequently inflamed or infected, causing intestinal discomfort and pain.

Enema: A procedure during which fluid is passed into the rectum through a tube inserted in the anus. An enema may be used as a treatment or to clear the intestine of feces in preparation for a diagnostic test.

Excision: The act of surgical removal, or the “cutting out,” of tissue from the body.

Familial adenomatous polyposis (FAP): A rare genetic disorder of the intestines characterized by “carpet-like” growths of polyps that develop along the inner walls of the colon. These areas of abnormal growth typically develop at a relatively young age.

Fecal Occult Blood Test (FOBT): A special test, also called a blood stool test, used to detect microscopic blood in the stool.

Gastroenterologist: A physician specially trained in the management of digestive system disorders.

Hemorrhoids: Widening of the veins in the anus causing itchy discomfort, pain, and bleeding. When hemorrhoids bleed it may be confused with bleeding due to other causes such as colon cancer

Hereditary nonpolyposis colon cancer (HNPCC): A rare, genetic condition that greatly increases an individual’s risk of colon cancer. For most people, polyps are not associated with HNPCC.

Herniation: A rip or tear in the musculature of the body, as a tear through the abdominal wall, pelvic floor or diaphragm.

Immunotherapy: An experimental therapy that helps the body to mount its own defenses against cancer by bolstering the immune system. Immunotherapy is also known as biological therapy.

Intravenous (IV) infusion: The delivery of fluids, drugs, nutrition, etc. through a small plastic tube inserted into a vein. The hands or arms are common sites for the establishment of an intravenous line.

Lymphatic system: A network of vessels, similar but distinct from the blood vessel system, that carries lymphatic fluid throughout the body. This fluid bathes the body’s tissues and contains specialized cells that help fight infection.

Malignancy: Uncontrolled division and growth of abnormal cells. These cancerous cells replace otherwise normal cells of the body.

Metastasis: A process by which cancer spreads through the body. Cancer may spread to an area near its original location or may reach other parts of the body through the lymphatic system.

Pathologist: A physician who specializes in the study of pathology or the evaluation of laboratory and functional tests to determine the nature or cause of a disease process. A pathologist’s report can provide valuable information that helps doctors to treat a variety of diseases, including colon cancer.

Polyps: Small, noncancerous growths in the moist, mucous membranes that line certain body cavities or organ systems. Polyps are most commonly found in the colon. They may eventually become cancerous and require surgical removal.

Radiation Therapy: The use of powerful beams of energy known as ionizing radiation to destroy cancer cells, thereby shrinking or eliminating a tumor.

Sigmoid: Literally, the “S-shaped” portion of the colon. This area of the colon is located between the descending colon and the rectum.

Sigmoidoscope: A specialized instrument used to examine the inner walls of the rectum and sigmoid colon. The device is a soft, flexible tube with a tiny video camera at the leading portion of the tube.

Sigmoidoscopy: A diagnostic procedure that uses a flexible viewing tube to allow the doctor to see the inner walls of the colon. During this procedure, a tube is gently passed into the colon through the anus.

Stoma: A temporary opening in the abdominal wall that allows the end of the small or large intestine to be brought through the abdomen and fastened onto the surface of the skin. This enables waste materials from the intestines to pass through the stoma and empty into a bag called a colostomy bag. This flexible bag is fastened to the skin around the stoma and fits close to the body.

Tumor: A growth or mass of cells in the body that may be benign (not cancerous) or cancerous.

Ulcerative colitis: An inflammatory bowel disease (IBD) characterized by chronic inflammation of the inner lining of the colon and rectum. Symptoms may include diarrhea, abdominal discomfort, cramping, and an urgent need to defecate.

Additional Sources Of Information: Colon Cancer

Here are some reliable sources that can provide more information on colorectal cancer.

American Cancer Society (ACS) 
Phone: (800) ACS-2345(toll-free hotline)

National Cancer Institute (NCI), Cancer Information Service 
Phone: (800) 4-CANCER
Phone: 800-422-6237

Preventing colorectal cancer:

National Cancer Institute: Colon and Rectal Cancer Home Page

What you need to know about colorectal cancer:

National Cancer Institute: Colorectal Cancer: reducing the risk

United Ostomy Association, Inc. 
Phone: 1(800) 826-0826

For information on inherited forms of colorectal cancer:

Intestinal Multiple Polyposis and Colorectal Cancer 
Phone: 301-791-7526

Hereditary Center Institute, Creighton University School of Medicine 
Phone: 402-280-1796

National Society of Genetic Counselors 
233 Canterbury Drive
Wallingford, PA 19086-6671

The NSGC prefers written requests to phone calls and will send a list of certified genetic counselors who specialize in career counseling, and the names of nearby centers for genetic counseling.

Genetic Alliance

The Colon Cancer Alliance

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