Factors implicated in the pathogenesis of gastric ulcer were studied simultaneously in seven patients with strictly defined type 1 gastric ulcer (single benign ulcer above the incisura of the stomach) and in six healthy controls. After ingestion of an ordinary solid-liquid meal, patients with gastric ulcer demonstrated gastric hyposecretion of acid, pepsin, and water; delayed gastric emptying of solids with normal emptying of liquids; and increased intragastric concentrations of bile acids. These functional abnormalities appear to be interrelated. Metoclopramide, administered orally in a double-blind fashion, ameliorated the defect in the emptying of solids and the high concentrations of bile acid in the gastric contents. The ability of this drug to break this interdependent cycle suggests the need for further clinical investigation.