Do you have chronic diarrhea?

February 13, 2013

By Charles Bedard, MD
Gastroenterologist, Minor & James

Many people suffer from chronic diarrhea, not realizing that many times the cause can be found and corrected. Chronic diarrhea is defined as loose stools that last for at least 4 weeks. It usually means more than 3 or 4 loose bowel movements per day. Chronic diarrhea can have a substantial negative impact on quality of life and overall health. Many people with this problem have to stay near a toilet and are afraid to even leave the house because of fear that they will not be able to control their bowel action. It is particularly troubling if there is associated incontinence.

Chronic diarrhea can be caused by intestinal infections, endocrine disorders, inflammatory bowel disease, food sensitivity or allergy and a side effect of medications. These problems can often be diagnosed with a careful history and appropriate diagnostic testing.

There is one particular disorder called microscopic colitis that is often left undiagnosed with resultant debilitating diarrhea. Episodes of diarrhea from this problem can last for weeks, months or years. There may be brief periods when the diarrhea goes into remission. This problem is particularly common in people over the age of 45 and especially in women. A common history is that of a woman with chronic diarrhea for the previous year or 2 which has severely compromised her quality of life.

The main forms of microscopic colitis are lymphocytic colitis and collagenous colitis. Lymphocytic colitis is manifested by an excessive number of white blood cells called lymphocytes in the colon wall which appear to cause diarrhea. Many scientists believes that this is an abnormal immune response attracting lymphocytes to the colon triggered by an unknown antigen or irritating substance in the colon. This immune response leads to a leaky colon wall with reduced ability to absorb electrolytes and minerals in the body and resulting in increased fluid secretion into the colon with resultant diarrhea . Collagenous colitis is likely an extension of the lymphocytic colitis process with development of a layer of collagen or scar tissue in the colon wall. Scientists believe that one's genes may make it more likely to develop microscopic colitis.

Investigation for this problem includes elimination of medications and checking for a history of certain infections which have been associated with microscopic colitis. Colonoscopy examination reveals a surprisingly normal-appearing colonic mucosa. It is necessary to do biopsies from several areas in the colon to finding microscopic abnormalities characteristic of this disease. One has to be looking for this diagnosis to find it.

Effective therapy is available for microscopic colitis which often leads to return of normal bowel movements and a considerable improvement in quality of life.

If you or someone you know suffers from chronic diarrhea, I would recommend consulting a gastroenterologist for further evaluation.