Influence of food and marker length on gastric emptying of indigestible radiopaque markers in healthy humans.

A simple, noninvasive radiographic method was used to investigate the influence of food and of marker length on gastric emptying of indigestible solids. Ten healthy human subjects who had fasted for 12 h exhibited more rapid emptying when solid radiopaque markers were ingested with water than they did when markers were ingested with a 400-kcal solid and liquid meal. Mean (+/- SE) emptying of markers that were 10 mm in length averaged 55% +/- 15%, 97% +/- 3%, and 100% 1, 2, and 4 h after ingestion of the markers with water, compared with 4% +/- 2%, 32% +/- 11%, and 64% +/- 12% emptying 1, 2, and 4 h after ingestion of markers with the meal (p less than 0.05). Ingestion of a second and third test meal significantly prolonged gastric emptying of indigestible markers (p less than 0.05). No significant difference in emptying of the 10- and 2-mm markers from the stomach was detected. These experiments indicate that gastric emptying of indigestible solids in humans is strongly influenced by food intake, but not by the particle lengths studied.