Gastric emptying of the solid and liquid components of an ordinary meal was evaluated by a dual isotopic technique in 36 patients referred to our hospital for early postprandial symptoms induced by various esophageal and/or gastric operations. Patients were classified as typical (n = 11), equivocal (n = 9) or improbable (n = 16) dumpers, in accordance with their presenting symptoms, as assessed before gastric emptying measurement. Patients with typical dumping symptoms displayed, as expected, significant acceleration of gastric emptying of liquids (t1/2: 18 +/- 6 min. vs. 48 +/- 7 min. in healthy controls; p less than 0.02), and also exhibited a dramatic enhancement of gastric emptying of solids (t1/2: 11 +/- 1 min. vs. 126 +/- 12 min. in healthy controls; p less than 0.001) and a complete loss of solid-liquid discrimination (7 +/- 6 min. vs. 78 +/- 7 min. in healthy controls; p less than 0.01). Mean gastric emptying rates for equivocal and improbable dumpers were not significantly different from those of healthy controls, but individual results were very heterogeneous; they included stasis, acceleration, or both disorders, and were not predictable by analysis of symptoms alone. Thus gastric emptying of solids as well as liquids is accelerated in symptomatic dumping patients, and objective evaluation of the emptying of both solid and liquid gastric emptying is essential in atypical dumpers, in order to characterize their disorders and prescribe the most rational treatment.