In a 6 to 12-week double-blind trial, the effect of cisapride (10 mg q.i.d.) was compared with that of placebo in 63 patients with esophagitis confirmed by endoscopy and/or biopsy. In only one patient (3%) in the cisapride group but in 43% of the placebo patients (p = 0.001), symptoms had not improved after 6 weeks. Forty patients continued treatment until week 12. At that time, control endoscopy showed a significantly (p = 0.005) higher rate of healing (no erosions, ulcers, or bleeding mucosa) in the cisapride patients (63%) than in the placebo patients (12%). At week 12, only three of the 21 cisapride patients still had moderate reflux symptoms, whereas eight of the 19 placebo patients had moderate or severe symptoms (p less than 0.05). Cisapride patients also took significantly (p less than 0.001) less antacids during the trial. These results show that cisapride, 10 mg q.i.d., heals esophagitis lesions and greatly reduces associated symptoms. The treatment was well tolerated.