Identifying Cause of Chronic Constipation First Step Toward Treatment
Michael Camilleri, M.D.

DEAR MAYO CLINIC:

What is the latest in treatment for chronic constipation? Years ago, I read that research was being done to treat this condition. I've suffered with this problem for more than 40 years and have continually been searching for a cure or just some relief.

ANSWER:

While the topic may not be considered polite conversation, constipation affects nearly 30 million Americans and costs more than $1 billion annually to evaluate and treat. An estimated 20 percent of adults and children experience constipation, although it is more common in women and people over 65. Chronic constipation is characterized by infrequent bowel movements -- typically fewer than three a week -- and difficulty passing stools.

For those who experience chronic constipation (meaning the symptoms are present for more than three months), the first step should be trying to identify the cause. Many people don't get enough fiber in their diet. In general, a person needs 12 to 20 grams of fiber each day for good bowel function. People who don't naturally eat enough fiber can take a fiber supplement, such as a fiber bar or Metamucil or Citrucel.

Fluid intake is also vital. Drinking a sufficient amount of water every day is important, but it may not solve your problem, because most water never reaches the colon. Some people may need to take an "osmotic" laxative, such as Miralax or Milk of Magnesia. These laxatives work by increasing the amount of water that is secreted within the intestines, producing softer, easier-to-pass stools. If neither fiber nor osmotic laxatives are effective, you may need to try a "stimulant" laxative, such as Dulcolax or Correctol.

After trying osmotic and stimulant laxatives, if you're still experiencing constipation, I recommend seeing a gastroenterologist to determine if underlying problems exist. Medications, such as those for blood pressure, and pain, and even antidepressants, may cause constipation. Be sure to review all current medications with your physician.

A gastroenterologist can determine other causes of constipation, such as if the muscles used for stool evacuation are spasming and preventing elimination. In other situations, an inflammation that may lead to narrowing of the colon, called diverticulitis, may be to blame. If you experience chronic constipation, unexplained weight loss or blood in the stool, don't try to self-diagnose and self-medicate. Instead, see a gastroenterologist and have a colonoscopy to determine the cause.

Some new drugs are available and others are being tested that may provide relief. An available drug called Amitiza works by increasing the amount of fluid that flows into the bowel, allowing the stool to pass more easily. Linaclotide is an experimental drug awaiting approval from the Food and Drug Administration (FDA). It also helps the body produce more water in the intestine to loosen stools. If approved, this drug may be available within four to six months. While probiotics -- dietary supplements or foods that contain "good" bacteria -- are getting a lot of attention lately, whether they actually help with constipation is unclear.

Mayo Clinic researchers have had success in clinical trials with a drug called A3309. This drug targets the recycling of bile acid in the body and inhibits bile absorption in the small intestine, allowing more bile acids -- natural laxatives that promote bowel movements -- to enter the colon to stimulate elimination. Patients who took A3309, compared to those who took a placebo, reported significantly less straining and softer stool during bowel movements. This drug is still in development and won't be available for a few years, pending FDA approval.

Finally, I tell my patients, "Never pass on the chance to pass a bowel movement." Many people ignore the urge to go, which can negatively affect the body's natural elimination process. Over the years, chronic constipation can result.

Michael Camilleri, M.D., Gastroenterology, Mayo Clinic, Rochester, Minn.

Medical Edge from Mayo Clinic is an educational resource and doesn't replace regular medical care.