Dysentery caused by Balantidium coli--report of two cases.

The authors present two cases of dysentery caused by Balantidium coli with numerous colonic ulcers, documented by colonoscopy and diagnosed by endoscopic biopsies. The positive rectal exudate in one case permitted the isolation and ultrastructural study of the trophozoites. The good response to tetracyclines in the younger patient was not repeated in the older patient, who died in septic shock despite antibiotic therapy. The authors report the endoscopic findings and comment on the differential endoscopic diagnosis between parasitic and other organic colitis in view of the rarity of these examples as isolated cases in Western countries.