We present a method for estimating volumes of abdominal organs using 3-D ultrasonography. In vitro validation experiments demonstrated excellent agreement between estimated and true volumes. In vivo estimations after ingestion of 500 ml meat soup showed greater antral filling and poorer emptying of the gallbladder in patients with functional dyspepsia (FD) than in healthy controls. Abnormal antral filling was associated with dyspeptic symptoms. The relationship between motility and transpyloric movements of luminal contents after ingestion of 500 ml meat soup was studied in healthy subjects by duplex technique. Accurate timing of antegrade and retrograde flow were recorded using bidirectional velocity curves. Mid-cycle and end-cycle reflux were often observed; end-cycle reflux was more frequent in conjunction with coordinated than with uncoordinated antroduodenal contractions. The peristaltic closure of the pylorus was normally preceded by a short gush of duodenogastric reflux.