A double-blind, placebo-controlled trial was performed to determine the therapeutic efficacy of cisapride in patients with refractory functional dyspepsia. A total of 147 patients with functional dyspepsia characterized by prominent epigastric pain or discomfort were randomized to 2 weeks' treatment with metoclopramide or domperidone (both 30 mg/day); of these, 53 patients unresponsive to dopamine antagonist treatment were randomized to cisapride 30 mg/day or placebo for an additional 2 weeks. Metoclopramide and domperidone produced comparable alleviation of epigastric symptoms; global efficacy was good or excellent in 62% and 57% of patients, respectively. In refractory patients, cisapride tended to display greater efficacy than placebo against epigastric pain, particularly at night. Global assessments of efficacy significantly favored cisapride over placebo, with good or excellent ratings in 65% and 32% of patients, respectively. Cisapride was well tolerated. Thus, cisapride appears to be an effective agent in functional dyspepsia unresponsive to other gastrokinetic agents.