MICROSCOPIC COLITIS IS A CAUSE OF LARGE-BOWEL DIARRHEA IN NORTHERN INDIA

Chronic diarrhea is a common clinical problem. To determine the possib le causes in North India, we studied prospectively 71 patients with ch ronic diarrhea of the large bowel type. A definite diagnosis could be established in 70 patients. Ulcerative colitis was found in 18 patient s, colorectal malignancies in three, colonic polyps in three, and irri table bowel syndrome in 32. In addition, seven patients with seronegat ive polyarthritis and chronic diarrhea were found to have chronic infl ammation of the colon on histology. Two patients had pseudodiarrhea, a nd no diagnosis could be established in one patient. The remaining fiv e patients with chronic diarrhea showed histologic evidence of chronic colonic inflammation with predominantly mononuclear cell infiltration of the lamina propria and increased intraepithelial lymphocytes, but results of their radiologic and endoscopic studies were normal. These five patients were classified as having microscopic (lymphocytic) coli tis. We conclude that the causes of chronic diarrhea in North Indian p atients are similar to a large extent to those seen in Western populat ions. Microscopic (lymphocytic) colitis is a definite clinicopathologi c entity that should be considered in the differential diagnosis of ch ronic diarrhea.