Lymphocytic Colitis (cont.)

The cause(s) of microscopic colitis is unknown. Some doctors suspect that microscopic colitis is an autoimmune disorder similar to the autoimmune disorders that cause chronic ulcerative colitis and Crohn's disease.

One study has implicated long term (longer than 6 months) use of nonsteroidal antiinflammatory drugs (NSAIDs) as a cause of microscopic colitis. Some individuals' diarrhea improves after stopping the NSAIDs.

The primary symptom of microscopic colitis is chronic, watery diarrhea. Individuals with microscopic colitis can have diarrhea for months or years before the diagnosis is made. Typically, the symptoms begin very gradually and are intermittent in nature with periods when the person feels well, followed by bouts of chronic diarrhea. This chronic diarrhea of microscopic colitis is different from the acute diarrhea of infectious colitis, which typically lasts only days to weeks. Some individuals with microscopic colitis also may experience mild abdominal cramps and pain. Blood in the stool is unusual.

The prevalence of microscopic colitis in the U.S. is not clearly known. It is estimated that 10% to 20% of persons with chronic diarrhea may have microscopic colitis. It is this author's experience, that the condition is becoming more common in recent years. It is not clear, however, whether there is an actual increase in the frequency of microscopic colitis or whether doctors are just better at diagnosing it.

Microscopic colitis most commonly occurs in middle aged to elderly patients and is more common among women than men.

Source: MedicineNet.com
http://www.medicinenet.com/lymphocytic_colitis/article.htm