The dumping syndrome following gastric surgery for peptic ulcer disease can cause severe morbidity. In this study the benefit of interposition of an antiperistaltic jejunal loop to reverse peristalsis and delay gastric emptying was assessed in four patients with severe symptoms by performing gastric emptying studies pre-operatively, and at 6 months and 24 months following surgery. Gastric emptying was delayed at 6 months but by 2 years had returned to pre-operative values. Patients' symptoms were improved at 6 months and remained so despite the deterioration in gastric emptying. This surgical procedure is of some value to patients with severe symptoms due to the dumping syndrome.