Mayo Clinic develops new way to rate severity of colitis, a common cause of diarrhea

Mayo Clinic researchers have developed a new way to assess a common cause of chronic diarrhea, microscopic colitis, using the Microscopic Colitis Disease Activity Index. A study describing the index was released today during the American College of Gastroenterology 2011 Annual Scientific Meeting and Postgraduate Course in Washington. The index provides a consistent way to assess the condition's severity.

"Until now, physicians have not had a way to objectively and consistently score the severity of a patient's disease beyond simply counting the number of bowel movements per day," says author Darrell Pardi, M.D., a Mayo Clinic gastroenterologist. The assessment also accounts for symptoms other than diarrhea, such as abdominal pain, urgency, and incontinence.

"This assessment is a significant step forward, as it correlates a patient's symptoms with the physicians' understanding of the severity of microscopic colitis," Dr. Pardi says. Using the assessment index in future studies, researchers will more easily compare treatments for this condition.

Microscopic colitis is recognized as a common cause of chronic diarrhea, causing perhaps 30 percent of all cases of the condition in older patients. Microscopic colitis is a chronic, inflammatory condition of the large intestine (colon) that causes watery diarrhea and, sometimes, abdominal pain. The disorder gets its name from the microscopic examination of tissue required to identify it.