The side effects of the removal of a functioning gallbladder are surprisingly few, and it has been suggested, but never demonstrated, that the hepatobiliary tract then adjusts to compensate for the loss of gallbladder function. In this study the effects of cholecystectomy on bile acid kinetics, bile flow, and biliary clearance of mannitol were studied in cats 6-8 weeks after cholecystectomy. An enhanced recycling rate of a diminished bile acid pool was found. The bile flow was reduced and the bile acid concentration in hepatic bile was increased, but fasting bile acid secretion rate was not changed. Both when the bile acid secretion rate was reduced by drainage via an acute bile fistula and when it was enhanced by intravenous infusion of glycocholic acid, there was a lower bile acid-independent flow in the cholecystectomy group. This reduced bile flow after cholecystectomy was not explained by the higher proportion of deoxycholic acid present in the bile of the cholecystectomized animals. Biliary clearance of mannitol, which is supposed to reflect the canalicular inflow, was not reduced, indicating that the reduction in bile flow is explained by a reduced fluid secretion or an enhanced fluid reabsorption in the bile ductules and ducts after cholecystectomy. In this manner the bile ducts compensate for the loss of the absorptive function of the gallbladder after cholecystectomy.