Microscopic colitis and collagenous colitis. An entity not yet reported in Chile

Collagenous and microscopic colitis have been described as causes for abundant watery diarrhea with a normal radiologic and endoscopic aspect of the colonic mucosa. Microscopic colitis is characterized by diffuse intraepithelial lymphocytic infiltration and collagenous colitis by thickening of subepithelial collagen layer greater than 15 microns with or without inflammatory changes of the mucosa. Here are reported 5 patients with microscopic colitis and 4 with collagenous colitis. The mean age was 52 years (range 40 to 68) with an equal sex distribution. Diarrhea was of longstanding duration without weight loss, anemia or hypoalbuminemia. Occasionally the volume of diarrhea was over 1 L a day. One patient had steatorrhea that proved resistant to a gluten free diet. Endoscopic and radiologic findings were normal in every patient and the diagnosis was based on typical histology. Azulfidine therapy was successful in 7 patients and prednisone in another. Colonic biopsy should be performed in every patient with chronic diarrhea.