A sequential scintiscanning method was used to study gastric emptying in a total of 46 patients given a meal of cornflakes, sugar and milk containing radioactive markers of the solid and liquid components. In control and duodenal ulcer patients, liquid emptying was faster than solid emptying and could be represented as a monoexponential process, but solid emptying followed a different pattern, better represented as linear emptying with time. However, in patients who had undergone Billroth II gastrectomy there was no evidence of differential emptying of the two markers. In addition, rapid emptying of both markers occurred in the gastrectomy patients during the first 10 min after meal ingestion but did not occur in control or duodenal ulcer patients. The observations illustrate the limitations of using liquid meals to identify the effects of gastric surgery on emptying. Measurements of early emptying and of solid-liquid differentiation are necessary for full definition of gastric emptying after ingestion of a mixed solid and liquid meal.