Gastric fluid detected by sonography in fasting patients: relation to duodenal ulcer disease and gastric-outlet obstruction.

We correlated the amount of gastric fluid identified by sonography in 143 fasting patients with the presence of duodenal ulcer disease and gastric-outlet obstruction as seen on barium studies. Unselected consecutive patients who were referred for a barium study of the upper gastrointestinal tract were included in a double-blinded prospective study. Sonograms were obtained in the right lateral decubitus position to allow gastric fluid to accumulate in the antrum, where it was quantified by measuring the maximal cross-sectional area of antral fluid in square centimeters. Sonograms revealed no fluid or a small amount (less than 5 cm2) in 87 (61%) of the patients and a large amount of fluid (greater than or equal to 5 cm2) in 56 patients (39%). Barium examinations showed a duodenal ulcer in 26 (46%) of the 56 patients with sonographic evidence of a large amount of gastric fluid compared with 10 patients (11%) in the group with little or no fluid on sonography (p = .001). Sonographic evidence of a large amount of fluid was found in all five patients who had gastric-outlet obstruction on barium examination (p = .02). The detection of a large amount of fluid in the stomach on sonography appears to be a feature of duodenal ulcer disease and gastric-outlet obstruction.