OUTLINE: This is a prospective, randomized, parallel, open label, multicenter study. Patients are stratified by therapy, grade of diarrhea, and prior use of loperamide hydrochloride or octreotide acetate. Patients undergo 1 of 3 treatments. Patients receive either low doses of octreotide (arm A) or high doses of octreotide (arm B) subcutaneously 3 times daily for 5 days. Patients in arm C receive oral doses of loperamide following each unformed stool for 5 days. A diary is completed by patients to record medications and bowel history. Treatment continues if diarrhea persists beyond day 5, but will be considered a treatment failure. If diarrhea continues to worsen, patients are removed from study. All patients are followed for 24 days.