OBJECTIVE To determine the nature of reflux after esophagectomy and interposition of right colon. METHODS A case series. METHODS A university hospital. METHODS Five patients (mean age 43 years) in whom right colon had been interposed after total esophagectomy. METHODS Endoscopy and biopsy, manometry, 24-hour ambulatory pH testing. METHODS Endoscopic and histologic appearances of the colon, type of motor activity in the grafted colon and the type of reflux. RESULTS In all patients the grafted colon was macroscopically and microscopically normal. There was nonperistaltic motor activity in the interposed colon in two patients. All patients had an abnormal pattern of alkaline reflux, and one patient had abnormal acid reflux. CONCLUSIONS The clinical effect of alkaline reflux in patients with colonic interposition after total esophagectomy may be slight. Histologic and gross changes are likely to be minimal.