Cholescintigraphy with technetium 99m hydroxy imino diacetic acid (99mTc-HIDA) was used to study gallbladder emptying (GE) and duodenogastric reflux (DGR) simultaneously during the postprandial period in humans. Two groups of subjects were examined prospectively; one was a group of healthy volunteers (n = 14) and the other a group of patients with non-ulcerous dyspepsia (NUD) (n = 22). Symptoms were quantified using a clinical score (CS). GE kinetics was quantified according to two indices. DGR episodes were detected by an image-subtraction method and quantified. The group of patients with NUD showed significant early acceleration of GE (P less than 0.01). One DGR episode equivalent to 1% of the injected dose was observed in 1 of the 14 control subjects, and greater than 1% in 3 of the 22 NUD patients. However, there was no correlation between the CS, GE kinetics and DGR episodes. The physiopathological mechanism and clinical significance of these digestive motility anomalies remain to be demonstrated.