Lymphocytic colitis, induced by ticlopidine.

Lymphocytic colitis is a chronic inflammatory colonic disease characterized by watery diarrhea and a dense infiltration of the colonic mucosa with lymphocytes. The etiology is unknown but an immune reaction to various immunostimulatory agents including pathogenic or commensal bacteria, products of bacterial metabolism of dietary degradation, or antigens derived directly from the diet, and autoimmune phenomena are discussed. We observed a patient with all features of lymphocytic colitis characterized by a prominent intraepithelial T-cell component. The colitis resolved completely when therapy with ticlopidine--an agent inhibiting platelet aggregation--was stopped. This observation suggests that medical history concerning drug ingestion may reveal the etiology of lymphocytic colitis and allows cure of this otherwise difficult to treat disorder.