So-called acalculous gallbladder disease is an ill-defined entity, mainly seen in young women, which could be due to a motility disorder of the biliary tract. Seven young women with relapsing pain in the right upper quadrant of the abdomen or in the epigastrium, with cholesterol crystals in the bile and with normal sonographic and radiologic findings as well as normal gastroscopy, were investigated by hepato-biliary scintigraphy with 99mTc-HIDA. This first group was compared with a second group of 6 young women suffering from irritable colon, and with a third group of 6 asymptomatic control subjects. The half emptying-time of the gallbladder after cholecystokinin injection was 104.36 +/- 43.93 minutes in the first group, 17.92 +/- 23.57 minutes in the second and 20.42 +/- 23.67 minutes in the third group (p less than 0.005). After 6 weeks of ursodeoxycholic acid treatment, regression of pain and a significant reduction in the half emptying-time from 104.36 +/- 43.93 to 74.35 +/- 52.79 minutes (p less than 0.01) was observed in the first group. These results, which need to be confirmed by further studies, show that in acalculous gallbladder disease there is a delay in gallbladder emptying which could explain the formation of cholesterol crystals by bile stasis as described by various authors.