The effect of Octreotide (SMS 201-995), synthetic somatostatin analogue on small intestinal and colonic fluid secretion induced respectively by cholera toxin (CT) and deoxycholic acid (DCA) was investigated in rabbits using in vivo isolated loops. After exposure to CT and DCA, marked fluid accumulation was observed in the small intestinal and colonic loops, along with elevation of jejunal and colonic mucosal cyclic AMP concentrations. Octreotide inhibited CT and DCA induced small intestinal and colonic secretion, dose-dependently. This anti-secretory effect was observed after both intramuscular and oral administration of octreotide. In contrast, octreotide did not affect the elevated mucosal cyclic AMP concentrations. These results suggest that octreotide inhibits CT and DCA induced intestinal secretion, and this anti-secretory effect is produced by affecting processes beyond cyclic AMP formation.