Information about Infrequent Bowel Movements & Difficulty Passing Stool

Constipation is a symptom that can stem from a number of medical conditions, including lower digestive tract disorders. Nearly everyone has had a bout of constipation—infrequent bowel movements and difficulty passing stool—at some point in their lives. It becomes more common with age and occurs in at least 25 percent of people over age 65.

In most cases, constipation is not a serious condition and can be treated with lifestyle measures, such as increasing your intake of dietary fiber and level of physical activity or taking a laxative.

Causes of constipation

Constipation typically occurs when fecal matter moves too slowly through the colon. This allows the body to absorb too much water from the stool, leaving it dry and hard. Many experts no longer believe that a low-fiber diet is a major contributor to constipation. However, ignoring the urge to have a bowel movement and changing one's daily routine, such as during travel, are contributing factors.

Constipation can also be a side effect of medication, including pain medications (mainly narcotics), antidepressants, diuretics, iron supplements, and aluminum-containing antacids. Some experts think that excessive use of laxatives also may lead to constipation, because the colon becomes dependent on the laxative to initiate defecation. Overuse of enemas can have the same result.

Various medical conditions also can cause constipation. These conditions include

  • Parkinson's disease
  • diabetes
  • multiple sclerosis
  • stroke
  • lupus
  • decreased thyroid function
  • spinal cord injuries

Constipation can also be a symptom of irritable bowel syndrome. Tumors in the colon and diverticulosis can cause constipation by blocking the passage of fecal matter. Last, constipation can result from mental health problems, for example, depression and eating disorders.

Symptoms of constipation

What is considered normal in terms of the frequency of bowel movements varies from person to person. In fact, having only three bowel movements a week is just as normal as having three bowel movements a day. Therefore, a sudden decrease in your typical number of bowel movements is a better indicator of constipation than your actual number of movements.

If untreated, constipation can lead to complications. Straining during bowel movements can irritate or cause hemorrhoids or rectal prolapse (when part of the lining of the rectum pushes out of the anus). Hard stools may lead to anal fissures—tears in the skin near the anus.

All of these conditions can cause pain, bleeding, or excessive secretion of mucus. Another potential complication is fecal impaction, an inability to have a bowel movement because the stool has formed a large, dense mass in the colon or rectum. You should call your doctor if you experience sudden and unexplained constipation, especially if it is accompanied by blood in the stool or severe abdominal pain, or if you experience constipation that lasts longer than a week despite making changes in your diet and physical activity.

Diagnosis of constipation

You are considered to have chronic constipation if you consistently average one or fewer bowel movements per week for at least a year or have at least two of the following signs of constipation:

  • two or fewer bowel movements per week
  • straining during at least one quarter of bowel movements
  • passage of pellet-like or hard stools during at least one quarter of bowel movements
  • feeling like not all of the fecal material is eliminated during at least one quarter of bowel movements

If you have a bowel movement fewer than three times a week but experience no discomfort or change in the pattern of your bowel movements, you likely aren’t constipated. Diagnostic tests like blood tests, abdominal x-rays, sigmoidoscopies, colonoscopies, and barium enemas are not helpful—or necessary—for the diagnosis of constipation.

Publication Review By: H. Franklin Herlong, M.D.

Published: 24 Mar 2011

Last Modified: 08 Sep 2015