We studied the gastric emptying of indigestible solids after the ingestion of radiopaque markers in 9 control subjects, 9 insulin-dependent diabetics and 9 dyspeptic patients. Along with a breakfast each individual swallowed 10 markers made of intravenous catheters filled with barium, then flat films of abdomen were taken 1, 2, 4 and 6 hours later. At fourth hour, all controls had emptied their markers, 11% of diabetics and 22% of dyspeptic patients (p < 0.001). By 6 hours, 33% of diabetics and 55% of dyspeptic subjects had emptied them (p < 0.001, p < 0.05). At 4 hour controls had discharged 10 markers, diabetics 2.5 +/- 0.6 and dyspeptic 4.9 +/- 0.7. By 6 hours diabetics emptied 4.9 +/- 0.7 and dyspeptic patients 7.9 +/- 0.6 markers. Through this reliable method, an evident delay of gastric emptying in diabetics and a good proportion of dyspeptic patients is showed.