Normally, people have bowel movements at fairly regular intervals, and stool passes out of the body easily without much straining or discomfort. Although the normal frequency of bowel movements varies from person to person, about 95% of healthy adults have a pattern that ranges from three times a day to three times a week.
In constipation, bowel movements either occur less often than expected or the stool is hard, dry and difficult to pass. Most of the time, constipation is not related to an illness or digestive disorder. Instead, the problem is caused by diet, lifestyle, medications or some other factor that hardens the stool or interferes with the stool's ability to pass comfortably. Some common triggers of constipation in adults include:
- A diet low in fiber. You need about 25 grams to 30 grams of fiber every day to soften the stool and encourage proper bowel function. Most American diets contain less than half that amount.
- Inadequate fluid intake. To help prevent stools from becoming dry and hard, your daily diet should include at least six to eight "servings" of water. "Servings" can include full glasses of milk, juice and other beverages, but you also can count the water content in fruits, soups, stews and solid foods.
- A sedentary lifestyle. Because regular exercise is necessary to promote normal muscle contractions in the bowel wall, having a sedentary job or rarely exercising puts you at high risk of constipation.
- Ignoring the urge to defecate. If you have your bowel movements right after you feel an urge to defecate, this reinforces a normal nerve reflex that helps you to pass stool easily. Sometimes, because of a busy schedule or limited access to restrooms, a person ignores the urge to defecate. If you repeatedly postpone bathroom trips until a more convenient time, this can lead to constipation problems.
- Travel and scheduling factors. Travel can promote constipation by changing your diet, interfering with the normal timing of your meals, and limiting your access to restrooms.
- Laxative overuse. Long-term, regular use of laxatives can teach your bowel to rely on these medicines for help with bowel movements. Eventually, a laxative habit can contribute to your constipation, making you dependent upon continued laxative use.
- A side effect of medications. Constipation is a side effect of many prescription and nonprescription medications. Common problem medicines include iron supplements and vitamins that contain iron; calcium supplements; antacids that contain aluminum; antidepressants; drugs to treat schizophrenia or hallucinations; narcotic pain killers; general anesthesia; diuretics; muscle relaxants; and certain prescription drugs used to treat seizure disorders, Parkinson's disease, overactive bladder, and hypertension.
- Local pain or discomfort around the anus. An anal fissure or hemorrhoids can make bowel movements painful or uncomfortable. (An anal fissure is a small tear in the skin around the anus, and a hemorrhoid is a bulge from a vein in the anus.) To avoid pain, a person with one of these problems sometimes resists the urge to defecate. This can cause symptoms of constipation.
Less often, constipation may be a symptom of an illness or condition that affects the digestive tract, the brain or the spinal cord. Some examples include irritable bowel syndrome, intestinal obstruction, diverticulitis, colorectal cancer, hypothyroidism, abnormally high blood calcium levels (hypercalcemia), multiple sclerosis, Parkinson's disease and spinal cord injury.
Constipation is a very common problem that affects at least 80% of people at some time during their lives. In the United States, treatment for constipation accounts for more than 2.5 million visits to doctors' offices each year, with at least $800 million spent annually for laxatives. Although adults of all ages can suffer from constipation, the risk of this problem increases dramatically after age 65 in both men and women.
Occasionally, long-term constipation develops into fecal impaction, which is a blocked colon from a mass of stool that can't be moved by colon contractions. Fecal impaction can cause pain and vomiting, and a person with fecal impaction may require emergency treatment or hospitalization. Fecal impaction is a fairly common complication of long-term constipation in the elderly and bedridden, occurring in about 30% of all nursing home residents.
Symptoms of constipation include:
- Fewer than three bowel movements per week
- Small, hard, dry stools that are difficult or painful to pass
- The need to strain excessively to have a bowel movement
- A feeling that your rectum is not empty after a bowel movement
- Frequent use of enemas, laxatives or suppositories
Symptoms of fecal impaction include:
- Liquid stool (the stool is leaking around the impacted mass of feces and can be mistaken for diarrhea)
- Abdominal pain, especially after meals
- A persistent urge to move the bowels
- Nausea and vomiting
- Poor appetite, weight loss
- Malaise (a generally sick feeling)
- If the problem is not treated, dehydration, rapid pulse, rapid breathing, fever, agitation, confusion and urinary incontinence
Most people with simple constipation can diagnose and treat themselves. If you have constipation, begin by examining your lifestyle. Review your current diet, your level of daily exercise, and your bowel habits. In particular, do you often ignore the urge to have a bowel movement because it is inconvenient? Then take preventive measures, such as adding fiber to your diet, drinking plenty of fluid, and getting regular exercise. If this does not relieve your problem, contact your doctor.
If you have constipation together with rectal bleeding, abdominal pain or abdominal distention (bloating), contact your doctor immediately. It is best in this case for your doctor to evaluate you, including a physical exam and digital rectal examination.
If your symptoms indicate you might have fecal impaction, your doctor can confirm the diagnosis by examining your abdomen and by checking for a mass of impacted feces during the digital rectal exam. You may need other tests, including blood tests, plain abdominal X-rays, a barium enema or sigmoidoscopy (in which a special instrument is used to view the lower colon).
People 50 years and older are more likely to develop colon polyps or colon cancer. Constipation can be a symptom of colon polyps or cancer, and you should make sure that your screening for colon cancer (by colonoscopy or another test) is up-to-date.
How long constipation lasts depends on its cause. In most otherwise healthy adults, constipation improves gradually within a few weeks after they increase their intake of dietary fiber and fluid and begin exercising regularly. However, constipation in bedridden people with neurological problems can be persistent and is a risk factor for fecal impaction.
In many cases, you can prevent constipation by taking the following steps:
- Add more fiber to your diet. Set a dietary goal of 25 grams to 30 grams of fiber daily. Choose from a variety of high-fiber foods such as beans, broccoli, carrots, bran, whole grains and fresh fruits. To avoid bloating and gas, add these foods gradually over a period of several days.
- Drink adequate amounts of fluid. For most healthy adults, this is the equivalent of six to eight glasses of water daily.
- Begin a program of regular exercise. As little as 20 minutes of brisk walking daily can stimulate your bowels.
- Help train your digestive tract to have regular bowel movements. Schedule a 10-minute period to sit on the toilet at approximately the same time each day. The best time to do this is usually right after the morning meal.
- Do not postpone having a bowel movement until the time is more convenient. Respond to the urge without a delay.
- Use an over-the-counter stool softener or fiber supplement. This may prevent occasional constipation. Always follow the dosage instructions exactly as written on the labels of these medications.
If you have uncomfortable symptoms of constipation, the first step is ensure you are drinking enough fluids, and to increase your fiber intake. The fiber content of your diet by adding cereal grains, fruits and vegetables, or daily doses of a fiber supplement (for example, Metamucil or Citrucel). If constipation persists, it is reasonable to use a laxative treatment to help your bowel expel the stool. There are many laxatives available without a prescription, and they are safe for occasional use.
Salt-based or carbohydrate-based ("osmotic") laxatives use natural salts, magnesium salts or undigested sugars to help loosen stool by drawing water through the bowel wall into the bowel. Examples are milk of magnesia, lactulose, and polyethylene glycol (Miralax)
Stimulant laxatives, such as laxatives that contain senna, cascara or bisacodyl, are less gentle. Stimulant laxatives cause the colon muscles to contract more frequently or more aggressively.
Laxatives are available in forms that can be swallowed or inserted into the rectum as a suppository.
Enemas also can relieve constipation and are available at pharmacies without a prescription. An enema is a bag of liquid (usually a mixture of salt and water) attached to a plastic tube with a tapered tip. The enema fluid can be emptied into the rectum after the tip is inserted into the anus. The fluid is emptied when you lift the bag several inches and allow the fluid to move with gravity. An enema loosens stool in the rectum and triggers the rectal muscles to squeeze as a reaction to their being stretched.
If you have fecal impaction, your doctor may remove part of the fecal mass by hand, by using a lubricated, gloved finger inserted in the rectum. The rest of the mass usually can be removed with an enema. Rarely water irrigation through a sigmoidoscope is needed to clear a fecal impaction. Once the impacted stool is removed, your doctor will have you follow a high-fiber diet and may recommend a stool-softening medication or laxative to promote regular bowel movements.
Call your doctor immediately if your bowel movements stop and you develop abdominal pain or distention. Also contact your doctor immediately if you have any bleeding from your rectum.
Call your doctor for milder symptoms if you want advice or if constipation continues for longer than a couple of weeks, or if you need laxatives more than two or three times per week to help you move your bowels.
Most people with constipation can achieve normal bowel function through diet and lifestyle changes.
The outlook for most people with fecal impaction is good. However, it is common for fecal impaction to return if constipation is not improved with additional treatment. A long-term program of mild laxatives, periodic enemas or both may be necessary.
National Institute of Diabetes & Digestive & Kidney Disorders
Office of Communications and Public Liaison
Building 31, Room 9A04
31 Center Drive, MSC 2560
Bethesda, MD 20892-2560
American College of Gastroenterology (ACG)
P.O. Box 3099
Arlington, VA 22302
American Gastroenterological Association
4930 Del Ray Ave.
Bethesda, MD 20814