Prevalence of microscopic colitis in patients with symptoms suggesting irritable bowel syndrome.

Goals/background: Irritable bowel syndrome is a common disorder affecting 20% of the general population. It shows certain characteristics with organic bowel diseases. Definition of lymphocytic and collagenous colitis has created a new approach towards chronic idiopathic diarrheas. We searched for the frequency of lymphocytic and collagenous colitis in patients with irritable bowel syndrome.
Study: The study group consisted of 30 irritable bowel patients and 20 controls. Multiple biopsies from cecum; ascendant, transverse and descendent colon; sigmoid and rectum were taken sequentially in all patients.
Results: We diagnosed 7 out of 30 irritable bowel patients as having lymphocytic colitis (23.3%) but none as having collagenous colitis. In the control group 1 out of 20 patients had lymphocytic colitis (5%) and none had collagenous colitis. Irritable bowel patients had higher rate of lymphocytic colitis association (p < 0.05).
Conclusions: Functional disorders of the bowel should be searched for possible lymphocytic colitis, especially in cases refractory to classical therapies.