PURPOSE: The aim of this study was to compare the anatomic data obtained by magnetic resonance cholangiopancreatography (MRCP) with the functional data obtained by Tc-99m iminodiacetic acid (IDA) hepatobiliary imaging in patients with postcholecystectomy syndrome. MRCP provides good quality imaging of the biliary tract, highlighting walls and dilatation or stenosis of the biliary tract, stones in the cystic duct remnant, the pancreas, and the pancreatic ducts. Hepatobiliary imaging permits evaluation of hepatocellular function and the dysfunctional components of biliary obstruction. METHODS: MRCP showed biliary tract dilatation in four of five patients; this was associated with pathologic dilatation of the cystic duct and stenosis of the distal end of the common bile duct in three patients. Tc-99m IDA imaging showed hepatocellular functional changes (prolonged maximum concentration time and lower hepatic extraction fraction) in five of five patients, and delayed visualization of the hepatic duct and common bile duct in four patients. Intestinal passage of the radiopharmaceutical occurred in all patients only after a high-fat meal. Two patients had slow biliary emptying of Tc-99m IDA with normal results of MRCP. RESULTS: These data, together with the absence of structural changes in the biliary tract walls, suggest that sphincter of Oddi spasm during fasting causes slower passage, whereas the physiologic stimulation of a high-fat meal aids intestinal bile flow. CONCLUSION: The combined study of the biliary tract by MRCP and Tc-99m IDA imaging yields an efficient and complete evaluation of the postcholecystectomy syndrome.