What Is Constipation?

What Is Constipation?

Constipation is difficulty passing stool (moving your bowels) or the infrequent passing of stool. It is a common problem suffered by many people at some time during their life. Constipation is not a disease, but it can be a symptom of many diseases.

Although the frequency of bowel movements varies among different individuals, a person who has fewer than three movements each week is considered to have constipation.

Constipation is also used to describe the passage of small, hard stools or difficulty or pain on passing stool. It is sometimes used to describe bleeding, abdominal discomfort, and bloating associated with passing stools.

Great importance was previously attached to a daily “normal” bowel habit. However, doctors are gradually becoming more relaxed about this with the realization that there is a wide variation in normal bowel habits and there are no ill effects from a less regular pattern of moving your bowels.

Being constipated is generally not harmful, but it may lead to discomfort, feeling unwell, abdominal bloating and loss of appetite. These complaints are due to distention (swelling) of the colon rather than any ill effects arising from the constipation.

However, the inability to pass any stool at all indicates that there may be a blockage in the digestive tract that requires medical attention.

The best way to avoid constipation is to:

  • Drink plenty of fluids each day

  • Get enough exercise

  • Move your bowels as soon as you feel the urge to do so

  • Eat a diet that includes 25 to 30 grams of fiber each day


For more detailed information about getting enough fiber in your diet, go to Fiber: Its Importance In Your Diet.



Nice To Know:

The word “constipation” is derived from the Latin “constipare,” meaning “to press closely or to crowd together.”



Facts About Constipation

  • Almost everyone gets constipated at one time or another.

  • Constipation is common during pregnancy, after childbirth, and following surgery.

  • Fiber keeps stool soft and keeps the contents of the intestines moving. A good diet should contain approximately 25 to 30 grams of fiber a day, but the average American eats less than half of that.

  • Many people think they are constipated because they have infrequent bowel movements, but normal bowel movement can occur anywhere from three times a day to three times a week.


What Causes Constipation?

The most common cause of constipation in the western world is thought to be the lack of fiber in our diet.

  • Fiber adds bulk, which eases the passage of digested food through the intestine.

  • Fiber also absorbs water, which softens the stool.


Although most of the food we eat is absorbed in the stomach and small bowel, dietary fiber is not absorbed. The cell walls of plants – in particular, the fibrous outer coats of fruits, vegetables, seeds, and grains – provide the basis of fiber. Undigested carbohydrates, such as starch, also enter the colon and are broken down by bacteria, in a process called fermentation, which increases the bacterial population in the colon. The resulting increase in living and dead colonic bacteria causes a corresponding increase in stool size and softness.

Other simple causes of constipation include:

  • Inadequate food intake

  • Dehydration (not getting enough liquids)

  • Lack of physical activity.

  • Acute illnesses, particularly if the person is confined to bed, is unable to drink enough fluid, and has a poor appetite.


Constipation can be brought on or made worse by painful anal conditions such as anal fissures (splits in the tissue inside or the skin around the anus), hemorrhoids, or abscesses. Occasionally hernias, particularly in the groin, can cause constipation.

Constipation can also be a sign of other underlying conditions that affect the way in which the bowel works. The later stages of pregnancy are often accompanied by constipation, due to increased pressure from the enlarged womb pressing on the bowel, and aggravated by iron supplements that may be taken during pregnancy.

Other conditions that obstruct or block the bowel include cancer of the colon and other internal malignancies, diverticular disease, and strictures (narrowing of the bowel) caused by inflammation.


Need To Know:

Contact your doctor is you have sudden and lasting constipation or diarrhea with no obvious cause, especially if you have previously had regular bowel habits.


Some medical diseases such as diabetes or an underactive thyroid may also cause constipation. Nervous disorders such as Parkinson’s disease, multiple sclerosis, a stroke, and paralysis may cause constipation by altering the way in which the bowel works or by reducing a person’s ability to get enough physical exercise. Constipation may also be a side effect of drugs used to treat these conditions.

Giving up smoking may be followed by a short period of constipation, particularly in people who smoke a cigarette to stimulate their bowels into working.

Many medications cause constipation. Some of the more common drugs with this side effect include:

  • Drugs used for treating depression, including tricyclic antidepressants (such as amitriptyline, imipramine and nortriptyline) and monoamine oxidase inhibitors (such as phenelzine, isocarboxazid and tranylcypromine).

  • Diuretics or “water tablets” used in the treatment of heart failure or high blood pressure. These medications can cause dehydration, which in turn can lead to constipation.

  • Iron preparations taken by mouth may have a constipating effect, particularly in older people.

  • Antacids containing aluminum salts used for relieving indigestion.

  • Opiates (strong painkillers) such as morphine, demerol, oxycodone, and codeine.

  • Cough medicines that contain codeine as a cough suppressant.

  • Drugs used to treat Parkinson’s disease and epilepsy.



Need To Know:

Whenever your doctor prescribes a new medication, be sure to ask whether the drug causes constipation. If so, you can make appropriate dietary changes or take a mild laxative. Some laxatives may interfere with the absorption of other drugs, so be sure to consult with your physician before taking a laxative.


Who Gets Constipated?

Constipation can affect people of any age, but it is especially common in children and in the elderly.

Constipation in Babies and Children

Constipation is a common problem in babies and children, usually because of an inappropriate diet or insufficient fluid intake. Dietary changes are usually sufficient to , but a simple laxative may be needed for a short time.

If your child is constipated, the doctor will ask you detailed questions and will conduct a careful physical examination of the child. Underlying causes of constipation should be excluded. Possible physiological causes include an underactive thyroid, diabetes, constipating drugs, or abnormalities of the nervous system such as spina bifida. Occasionally, abnormalities such as narrowing of the anus or an anal fissure (which causes constipation because of the pain it causes on defecation) may need treatment. Illness, stress, and family upheaval may also cause constipation.

Sometimes children persist in refusing to pass stool and become chronically constipated. Initially, the child’s reluctance to pass stool could be caused by a painful fissure, too-early attempts at bowel training, emotional problems, or other reasons. When constipation becomes chronic, the colon is distended by the build-up of stool. Overflow of loose stool, with continual soiling of the underclothes, may cause distress to the child and parents.

Treatments include increased dietary fiber and the use of a simple laxative to stimulate a bowel movement. Bowel training, with plenty of positive reinforcement, and follow-up care are important until normal bowel habits are restored.

Children with severe behavioral problems may persistently pass stool in abnormal places, such as behind the furniture or curtains, and may need to be seen by a child psychiatrist.



Need To Know:

Babies and young children who have constipation from birth, sometimes with vomiting and abdominal swelling, may have an underlying bowel abnormality. This unusual condition is called Hirschsprung’s disease (aganglionosis).

In babies and children with Hirschsprung’s disease, the nerves normally present in the in the lower few inches of the bowel are absent. The lower bowel consequently fails to work. The condition is diagnosed by taking a biopsy (a small section of tissue removed for study under a microscope) of the lining of the rectum. Surgery is necessary to remove the affected colon and join healthy bowel to the rectum.



Constipation In The Elderly

Men and women of advanced age are equally affected by constipation. Reasons for constipation in the elderly include:

  • Poor diet

  • Limited mobility

  • Side effects from medications

  • Depression


How Is Constipation Treated?

Simple lifestyle changes can often help relieve constipation:

  • If possible, avoid taking drugs that may be causing the constipation.

  • Avoid the long-term use of laxatives.

  • Drink sufficient fluid (at least 8 eight-ounce glasses) each day.

  • Get regular exercise. Walking is an excellent activity.

  • Pass stools as soon as the urge comes on. It helps to try to establish a regular pattern. Often a glass of juice or a cup of coffee or tea first thing in the morning will stimulate the bowels to work.


MEL_036 (Eyewire)


People who experience constipation should also constipation increase their intake of dietary fiber. Roughage or undigested fiber in the gut increases the rate of passage of food residues through the body. In addition, the stool will have more bulk, will be softer, and will pass more easily.

Foods rich in dietary fiber include:

  • Most vegetables, particularly root vegetables (such as potatoes, carrots, beets and onions)

  • Spring greens

  • Lentils

  • Whole oats

  • Barley

  • Corn

  • Beans

  • Nuts

  • Fresh or stewed fruit

  • Brown rice

  • Whole wheat flour

  • Bread

  • Pasta

  • High-fiber breakfast cereals (look for cereals containing bran)


Fiber eaten in the diet can be supplemented with natural or unprocessed bran. Most supermarkets or health food stores carry natural bran. Although it is rather dry and unpalatable, natural bran can be added to other foods or cereals. Start with 1 tablespoonful of bran daily and gradually increase the amount. Up to 3 tablespoonfuls – the equivalent of 30 grams of dietary fiber – may be taken daily.

Abdominal bloating, discomfort, and gas may increase during the first two weeks after bran is added to the diet, but these symptoms should gradually subside. The amount of bran required for each person varies significantly, so you may need to experiment to determine the right amount for you.

In a very small number of people, constipation may actually become more severe with added dietary fiber. If this occurs, consult your physician.

For more detailed information about getting enough fiber in your diet, see Fiber: Its Importance In Your Diet.


The Use Of Laxatives

Used judiciously, laxatives can be an effective aid in relieving constipation. Regular use of laxatives is seldom needed if a high-fiber diet is eaten and plenty of liquids consumed. Laxatives should only be used regularly on the advice of your doctor.

While hundreds of commercial preparations are available, laxatives fall into four broad types:

  • Bulk-forming

  • Stimulating

  • Lubricating

  • Osmotic


Remembering the four basic types can help you to determine which laxative to use.

Bulk-forming laxatives are the most commonly used and should be taken with plenty of fluids. These agents consist of indigestible fibers and are not habit-forming. The laxative effect is due to the absorption and retention of water in the stool, thus forming a larger, softer stool. It usually takes 1 to 3 days for the laxative to take effect.

Natural or unprocessed bran is as effective as commercial fiber preparations, but people are sometimes unable to tolerate it and may prefer a product such as:

  • Psyllium seed preparations (Hydrocil, Konsyi, Metamucil)

  • Methylcellulose (Citrucel)

  • Polycarbofil (Fibercon)


Stimulating laxatives chemically stimulate the bowel wall, increasing fluid secretion and muscle activity. They work either by causing irritation of the lining of the bowel or by direct stimulation of the nerves in the bowel. They often cause abdominal cramps and usually act within several hours to one day. Long-term use should be avoided as they may damage the bowel permanently, causing further constipation.

Stimulant laxatives include Bisacodyl (Dulcolax), Cascara, Castor Oil, Casanthranole (Pericolace), Phenolphthalium (Ex-Lax, Correctol), Senna (Senokot).

Lubricating laxatives, also called stool softeners, work by increasing the water content of stool. Various preparations are available, including liquid paraffin (Petrolatum), docusate (Colace, Surfak), and mineral oil.

Osmotive laxatives cause excess fluid to be retained in the bowel. These laxatives should be taken with adequate amounts of water, and long-term use is not recommended. They include saline laxatives, magnesium sulfate (Epsom salt), milk of magnesia, magnesium, citrate, and sodium phosphate.


Evacuating The Lower Bowel

Suppositories (medication inserted into the rectum) are useful for evacuating the lower bowel, and they usually act within 30 minutes. Glycerine suppositories are most commonly used. Medicated suppositories are also available, containing bisacodyl or dioctyl sulfosuccinate. Long-term use is not recommended.

Enemas (introducing a certain amount of water into the rectum as a way to flush the contents of the bowels) are also useful for evacuating the lower bowel. Warm tap water or warm saline enemas work well.


Treatment Of Severe Constipation

The initial treatment of anyone with constipation, after a complete medical history and physical exam have been done, is to provide adequate fiber and fluid in the diet. If this does not improve the condition, additional tests may be needed to determine the cause.

Subsequent therapy is directed at correcting the underlying disorders.

  • Biofeedback is useful in correcting disorders of the pelvic muscles.

  • Surgery may be necessary to correct disorders such as rectocele (a bulge of the rectum into the vagina), rectal prolapse where part of the rectum protrudes through the anus, and extremely slow colon transit (slow movement of the stool through the colon).


Tests for Constipation

If a simple cause for constipation is identified, such as a low intake of dietary fiber, no tests are needed. If the constipation is persistent, a simple blood test may be taken to make sure the thyroid gland is working normally. Constipation that comes on suddenly with no apparent cause (especially if there is blood in the stool) should be investigated further, especially in those over age 50, who are at higher risk for colon cancer.

The doctor will initially examine the rectum and anus. This usually includes a sigmoidoscopy, where an endoscope (a lighted tube) is inserted through the rectum and into the lower bowel to check for abnormalities. Additional tests may be ordered, such as a barium enema (an X-ray of the colon using a solution of barium) or colonoscopy (an examination of the entire colon with an endoscope).

These tests exclude serious diseases or tumors that may cause constipation. However, they give no information about how the bowel is functioning. For someone with severe constipation that does not improve with dietary changes, tests to check the function of the bowel may be necessary. They are painless and simple to perform:

  • A colonic transit study measures the number of days (or hours) it takes for a small marker to pass through the colon and be eliminated from the body. The marker is a group of small rubber rings taken in a dissolvable capsule. The progress of the rings is followed by a series of X-rays (usually a total of two or three X-rays) taken over a week-long period. It is important that an adequate amount of fiber is taken during the length of the study, and that no laxatives are used. A normal colon transit time varies between 24 and 72 hours. Severe constipation due to prolonged transit times may be improved by surgery to remove part of the colon.

  • Defecography is a method of observing the function of the rectum and pelvic muscles during defecation (elimination). A small enema of barium paste is placed into the rectum. The person is asked to eliminate the barium while X-rays are taken. This allows the doctor to visualize disorders of defecation, such as abnormal contraction of the pelvic muscle (puborectalis muscle), internal rectal prolapse, rectocele, and other conditions.

  • Anal manometry is a procedure in which a small balloon is placed in the rectum and measurements are made of the rectal sensation, the anorectal reflex, and the anal muscle activity.


Frequently Asked Questions


What causes constipation?

Constipation is frequently caused by a lack of fiber in the diet, but can also be due to not eating enough, not drinking enough, lack of exercise and certain illnesses or medications.


I typically move my bowels about three times a week. Am I constipated?

Probably not. It depends on what’s normal for you. People move their bowels anywhere from three times a day to three times a week.


Is it harmful to take laxatives for long periods of time?

Laxatives are usually only taken for short periods of time, especially stimulating and osmotive laxatives, which can damage the bowel with long-term use. Bulk-forming and lubricating laxatives are not habit forming.


Is constipation harmful to my health?

No, being constipated is generally not harmful, but it may lead to discomfort, feeling unwell, abdominal bloating and loss of appetite.


Sources Of Information

Intestinal Disease Foundation
(412) 261-5888


National Digestive Diseases Information Clearinghouse



National Institute of Diabetes & Digestive & Kidney Diseases


International Foundation for Functional Gastrointestinal Disorders (IFFGD)

American College of Gastroenterology

(703) 820-7400


Related Topics

Leave a Reply

Your email address will not be published. Required fields are marked *

Scroll to Top