Microscopic colitis: a report of two cases.

Microscopic colitis is characterized by chronic, watery, secretory diarrhea, with a normal or near-normal gross appearance of the colonic mucosa. Biopsy is diagnostic and usually reveals either lymphocytic colitis or collagenous colitis. The symptoms of collagenous colitis appear most commonly in the sixth decade. With collagenous colitis, the major microscopic characteristic is a thickened collagen layer beneath the colonic mucosa, and with lymphocytic colitis, an increase number of intraepithelial lymphocytes. Clinically, collagenous colitis is characterized by long-standing diarrhea. In patients with lymphocytic colitis, the duration of diarrhea is usually shorter and female predominance is less apparent. We report two cases of lymphocytic colitis in elderly women. Both presented with watery diarrhea of two month duration and weight loss. Extensive investigations were done and several medications failed to stop their diarrhea. Biopsy revealed lymphocytic colitis. Their diarrhea responded well to cholestyramine.