The atypical colitides.

Collangenous colitis is a clinicopathologic syndrome characterized by (1) chronic watery diarrhea and crampy abdominal pain and (2) distinctive colorectal histopathology that includes a subepithelial collagen band, prominent chronic inflammation in the lamina propria, and increased intraepithelial lymphocytes. Lymphocytic colitis has similar clinical features to collangenous colitis, the main symptom being chronic watery diarrhea. Diversion colitis is an inflammatory process that arises in segments of the large intestine that are excluded from the fecal stream. This condition usually occurs in patients with ileostomy or colostomy when a mucous fistula or Hartmann's pouch has been left.