A blacktip reef shark (Carcharhinus melanopterus) with a history of recurrent eversion or prolapse of the valvular intestine, arrived at the Steinhart Aquarium in June 1996 and was placed in a mixed species shark display. The eversion soon reappeared, and the animal became thin and anorexic. The everted portion of the intestine was bitten by another shark and became infected. Treatment included force-feeding, manual reduction of the eversion, hydrocortisone suppositories held in place with purse-string sutures, and injections of enrofloxacin. All treatments ultimately failed, and the animal died in March 1997. Necropsy revealed that the intestine had separated into two segments at the distal portion of the pyloric stomach (duodenum); both ends were scarred and sealed off. It is suggested that a torsion (twisting along the long axis) of the intestine was responsible for the condition.