The new colitides, Collagenous, lymphocytic, and diversion colitis.

Three recently described colitides are collagenous, lymphocytic, and diversion colitis. Collagenous and lymphocytic colitis are similar inflammatory bowel disorders of unknown cause that present as chronic watery diarrhea in middle age. Diversion colitis occurs as the result of surgery in which segments of the large intestine are excluded from the fecal stream. The clinical and histologic features of these entities are discussed.