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Constipation and impaction

Medically reviewed by Last updated on Jul 10, 2023.

What is constipation and impaction?

Harvard Health Publishing

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:

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 can also be caused by abnormal positioning of pelvic organs (for example, sagging of the uterus, called "uterine prolapse"), or abnormal contraction of muscles in the pelvis.

Constipation is a very common problem that affects at least 80% of people at some time during their lives. 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 more likely to occur in the elderly and bedridden.

Symptoms of constipation and impaction

Symptoms of constipation include

Symptoms of fecal impaction include

Diagnosing constipation and impaction

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, an abdominal CT scan, or sigmoidoscopy (in which a special instrument is used to view the lower colon).

Constipation can be a symptom of colon cancer. The risk of colon polyps and colon cancer increases with age. People age 45 and older should be sure that they are up to date with screening for polyps and cancer.

Expected duration of constipation and impaction

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.

Preventing constipation and impaction

In many cases, you can prevent constipation by taking the following steps:

Treating constipation and impaction

If you have uncomfortable symptoms of constipation, the first step is to make sure you are drinking enough fluids, and to increase 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 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. A traditional enema is done with 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. 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.

When to call a professional

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.

Additional info

National Institute of Diabetes & Digestive & Kidney Disorders

American College of Gastroenterology (ACG)

American Gastroenterological Association

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.