Cisapride is a new prokinetic gastrointestinal agent which has been shown to be able to increase gastric emptying and intestinal transit time in experimental animals and in patients with preexisting motility alterations. Up to now, however, clinical research evaluating the activity of the drug in healthy subjects is very limited. We have therefore undertaken a placebo-controlled study to simultaneously investigate the effect of cisapride (20 mg p.o.) on gastric emptying and intestinal transit time of a balanced liquid meal in 9 healthy volunteers. Median gastric half-time was 60 min after cisapride, as compared to 73 min after placebo (p less than 0.05). Intestinal transit time was similar after cisapride (75 min) or after placebo (105 min). These data confirm that cisapride significantly increases the speed of gastric emptying also in normal subjects. The lack of effect on intestinal transit could be explained by the interindividual variation observed in our experiments.