Health Encyclopedia - Diseases and Conditions

Constipation

Definition of Constipation

Constipation is a decrease in the frequency of stool (the body's waste product) or difficulty in the formation or passage of stool.

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Description of Constipation

Constipation is determined in the colon (large intestine), which is responsible for packaging and eliminating stool.

As food moves through the colon, it absorbs water while forming stool. Muscle contractions (squeezing motions) in the colon push the stool toward the rectum (the lower 8 to 10 inches of the large intestine). By the time stool reaches the rectum, it is solid, because most of the water has been absorbed.

Constipation occurs when the stool becomes hard and dry (due to too much water absorption) and is unable to pass out of the body during a bowel movement.




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Causes and Risk Factors of Constipation

The common causes of constipation are:

  • Not enough fiber in the diet - The American Dietetic Association recommends 20 to 35 grams of fiber each day, but the average American eats about 5 to 20 grams a day. Examples of fiber-rich foods are unprocessed wheat bran, unrefined breakfast cereals, fresh fruits (except bananas), dried fruits, vegetables (except potatoes), grainy breads and legumes.
  • Not enough liquid - Liquids like water and juice add fluid to the colon and bulk to stools, making movements softer and easier to pass. Recommended daily consumption of liquid is eight, eight-ounce glasses (totaling 64 ounces) per day.
  • Lack of exercise
  • Medications - Some medications that can cause constipation are: analgesics (Codeine, Demerol, Perocdan), antacids (Maalox, Mylanta), anticholingerics (Donnatal), anticonvulsants (Dilantin), anti-depressants (Tricyclics), Beta-blockers (Inderal, Tenormin) iron and calcium supplements, pain medications, antispasmodics and diuretics.
  • Irritable Bowel Syndrome (IBS) - IBS is a common condition marked by chronic or occasional diarrhea, alternating with constipation and accompanied by straining and abdominal cramps. (see Health Profile: IRRITABLE BOWEL SYNDROME)
  • Lifestyle changes, such as pregnancy, aging and traveling
  • Laxative abuse - A laxative is a food or chemical substance that acts to loosen the bowels by softening and increasing the bulk of bowel contents, increasing the amount of water in the colon and lubricating the intestinal walls. Over time, laxatives can damage nerve cells in the colon and interfere with the colon's natural ability to contract.
  • Ignoring the urge to have a bowel movement
  • Diseases such as multiple sclerosis, Parkinson's disease, chronic idiopathic intestinal pseudo-obstruction, stroke, spinal cord injuries, diabetes, under-active and over-active thyroid gland, uremia (excess urine waste product), amyloidosis (accumulation in the tissues/organs of amyloid), lupus, scleroderma (an autoimmune disorder that affects the tissues/organs), colorectal cancer, depression, colon tumors, diverticulosis and Hirschsprung's disease.
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Symptoms of Constipation

Depending on your diet, age and daily activities, regular bowel movements can mean anything from three bowel movements per day to one every three days. If you are experiencing hard, compacted stools that are difficult or painful to pass, the urge to move the bowels (even though you just had a movement), or no bowel movement over three days for adults and four days for children, you may have constipation.

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Diagnosis of Constipation

Occasional constipation does not justify visiting a doctor, but if the constipation becomes a persistent problem, you should. The doctor will first take a medical history and ask about the symptoms, duration, frequency and consistency of the stools and bowel movements. Next, the doctor will examine the abdomen for any sign of a hardened mass and conduct a digital rectal exam (DRE). During the DRE, the doctor will insert a gloved, lubricated finger into the rectum to feel for any tenderness, obstruction or blood. In some cases, blood and thyroid tests may be necessary.

More extensive testing is reserved for people with severe symptoms. This testing may include a barium enema x-ray, sigmoidoscopy, colonscopy, colorectal transit study or anorectal function tests (anorectal manometry and defecography). A barium enema x-ray involves viewing the rectum, colon and lower part of the small intestine after filling the organs with a chalky liquid to make these areas visible. A sigmoidoscopy is an examination of the rectum and lower colon (sigmoid) using a viewing instrument called a sigmoidoscope.

A colonoscopy is an examination of the rectum and entire colon using an instrument called a colonscope. The colorectal transit study shows how well food moves through the colon. After swallowing capsules containing small markers, the markers’ movements are viewed via an x-ray.

An anorectal manometry evaluates anal sphincter muscle function. A catheter or air-filled balloon inserted into the anus is slowly pulled back through the sphincter muscle to measure muscle tone and contractions. Defecography is an x-ray of the anorectal area that identifies anorectal abnormalities, evaluates rectal muscle contractions and relaxation.

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Treatment of Constipation

Most cases of constipation respond to conservative treatment such as dietary and lifestyle changes or mild laxatives.

Dietary changes include getting enough of the recommended daily amount of fiber (20 to 35 grams), drinking 64 ounces of water or juice a day, and limiting foods that have little or no fiber, such as ice cream, cheese, meat and processed foods.

Lifestyle changes consist of exercising, reserving enough time to have a bowel movement and having a bowel movement when needed.

Laxatives may be recommended if the above changes did not help the constipation.

There are four types of laxatives - bulk-forming, stimulant, lubricant and saline. Bulk-forming laxatives, such as Metamucil, Citrucel and Serutan increase the volume of feces, making them softer and easier to pass. Stimulant laxatives, such as Correctol, Ex-Lax, Dulcolax, Purge, Feen-A-Mint and Senokot stimulate the intestinal wall to contract. Lubricant laxatives, such as mineral oil, soften the stool so it is easier to pass. Saline laxatives, such as Milk of Magnesia, Citrate of Magnesia and Haley's M-O, increase the concentration of salts within the feces.

Note: Laxatives can be habit-forming. If laxative use causes asthma, skin rash, dizziness, irregular heartbeat, dehydration, muscle cramping, nausea or other side effects, please see a doctor immediately.

Other treatment methods may include:

  • Bowel retraining - may provide relief for people who have gotten into the habit of ignoring the urge. If a tight schedule has produced a tight sphincter, it may help to sit on a toilet, with book in hand, about 20 minutes each morning to encourage a return of reflexes that have disappeared. Straining is not recommended, since it may lead to tightening of muscles that should be relaxed for comfortable defecation.
  • Rectal suppositories - helpful in providing lubrication and in stimulating the defecation reflex. They are usually composed of glycerin, which is sometimes blended with sodium sterate, a fatty acid. Bisacodyl-containing suppositories have added potency, because they act directly on the bowel to stimulate emptying.
  • Enemas - usually become attractive only when oral laxatives cannot do the job. Introducing water into the colon helps to stimulate defecation. "Disposable" enemas deliver a solution of highly concentrated, nonabsorbable salts into the rectum and sigmoid colon. These salts attract an outpouring of fluid into the bowel and thus promote bowel contraction. Oil-containing enemas are sometimes recommended as softeners for feces that have become hardened within the rectum.
  • Biofeedback - may be recommended for people with chronic constipation caused by anorectal dysfunction. Biofeedback involves using a sensor to monitor muscle activity displayed on a computer screen allowing for accurate assessment of body functions. With this information, the doctor helps the person learn how to use the anorectal muscles.
  • Surgery - Surgical removal of the colon may be an option for people with severe symptoms caused by colonic inertia (lack of movement in the colon) and unremitting extreme constipation.
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What Questions To Ask Your Doctor About Constipation

Are there any tests that need to be done to rule out any serious problems?

Are there any risks or side effects associated with these tests?

What is the cause?

What type of treatment do you recommend?

How effective is this treatment?

Are any of the current medications that could be causing the constipation?

How often should a person have a bowel movement?

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