ABSTRACTThe output of hepatic bile was studied in 3 unanesthetized dogs with permanent external common duct fistulas during infusion of cholecystokinin‐pancreozymin preparations. The doses were such that the secretin content was negligible. Infusion during fasting doubled the output. Infusion during digestion of food with bile gave either a decrease of the output or an initial increase followed by a decrease. These patterns appear to be related to the gastric and duodenal activity during the experiments. Physiologic or pharmacologic interventions on hepatic bile output should thus be evaluated only when side effects on gastro‐intestinal motility and secretion can be exclu