In the orlistat group, 14 participants had a baseline abnormality revealed by gallbladder ultrasound, including 8 participants with fatty liver infiltration or hepatomegaly and 3 participants with gallstones. Of these, 2 patients still had gallstones at the end of the study; the third patient did not have a follow-up examination. At the end of the study, 6 participants in the orlistat group were found to have asymptomatic gallstones not seen at baseline; 5 of these patients had lost large amounts of weight (8.2-29.4 kg) and 2 were siblings. Another patient had multiple gallstones on ultrasound at day 167 after a 15.8-kg weight loss and had a subsequent cholecystectomy.