PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Not specified Renal: Not specified Other: Concurrent enrollment into SWOG-9420 protocol allowed No sensitivity to octreotide acetate or loperamide hydrochloride Eligible if less than 24 hours since prior loperamide or octreotide and no resolution of diarrhea Not pregnant or lactating Effective contraception required of fertile patients Not HIV positive No idiopathic ulcerative colitis or Crohn's disease, acute stool culture positive bacterial colitis, pseudomembranous colitis, short bowel syndrome, enteroenteric fistulae, chronic pancreatitis, ischemic bowel disease, or gastrointestinal disorders known to cause diarrhea Absence of definitive culture results required