This study evaluates enterogastric reflux (EGR) levels in patients with and without symptoms of postoperative alkaline reflux gastritis (PARG) after gastric surgery. The bile acids (BA) present in the gastric juice were quantified by thin-layer chromatography and spectrofluorometry. The mean BA concentration for controls was 2.25 mumol reflux/hour, for 15 asymptomatic patients 47.94 and for 15 patients with symptoms of PARG 125.79. After biliary diversion by a Roux-en-Y anastomosis in the latter, their BA in 13 of these patients after surgery, and relapsed in only one during a 4-year follow-up. The remaining two patients had the lowest preoperative BA levels in this group. These results indicate that EGR is increased after gastric surgery more markedly indicated that EGR is increased after gastric surgery more markedly in patients with symptoms of PARG, and that patients who have high levels of EGR (more than 80 mumol BA reflux/hour) clearly benefit from biliary diversion.