Background: Two-dimensional ultrasonography has shown a widened gastric antrum in patients with non-ulcer dyspepsia (NUD) find erosive prepyloric changes (EPC). Methods: In this study, volumes of gastric antrum and gallbladder were estimated with three-dimensional (3D) ultrasonography before and after ingestion of 500 mi meat soup in 17 NUD with EPC patients and in 18 healthy subjects. A mechanical ultrasound scanner, coupled to a stepping motor, tilted the transducer through an angle of 51 degrees or 88 degrees while recording a total of 95 or 81 images, respectively. Volume estimation was performed digitally after interactive manual contour tracing and organ reconstruction in three dimensions. Results: Antral volumes were larger in NUD patients than in healthy controls (P = 0.001). Fasting gall bladder volumes were similar in the two groups. Postprandial antral filling was more pronounced in pa tien ts than in healthy subjects TP = 0.02), whereas gallbladder emptying was more pronounced in healthy subjects than in patients (P = 0.05). The soup induced dyspeptic symptoms in 15 NUD patients, but only had this effect in two healthy subjects (P < 0.001). Conclusion: Patients with NUD and EPC are characterized by abnormal antral filling, reduced gallbladder emptying, and dyspeptic symptoms in response to ingestion of meat soup.