OBJECTIVE An increased risk of gallstone development has been found in patients with Crohn's disease. This has been suggested to be due to abnormal bile acid metabolism. We investigated the possibility that Crohn's disease might alter gallbladder mechanical function and predispose to gallstone formation by incomplete emptying or prolonged contraction time of the gallbladder. METHODS Seventeen patients with Crohn's disease (CD) and 20 healthy controls (CO) of similar age and sex (CD: 7 males, 31 +/- 13 years; 10 females, 30 +/- 9; CO: 10 males, 26 +/- 12; 10 females, 26 +/- 9) were compared. None of the patients or controls had gallstones. Using ultrasonography with computed volume calculation, the gallbladder was assessed in fasting state and every 10 min for 70 minutes after ingestion of a standard fatty meal. RESULTS Neither maximum volume (CD: 22 +/- 9 ml, CO: 25 +/- 15), residual volume after stimulation (CD: 3 +/- 2 ml, CO: 6 +/- 6 ml), volume decrease in % (CD: 83 +/- 5%, CO: 78 +/- 9%), nor rate constants of emptying (CD: = 0.034/min, CO: = 0.033/min) were different between patients and controls. CONCLUSIONS Abnormal gallbladder contractility does not seem to be a major cause of an increased risk of gallstone formation in Crohn's disease.