Patients with abdominal pain, endoscopic evidence of gastritis and bile in the stomach, and no other obvious problems such as marginal ulcer are diagnosed as having reflux bile gastritis. Objective criteria for establishing the diagnosis are lacking. Since the incidence of bile reflux gastritis is much less than occurrences of reflux of bile into the stomach, the concentration and composition of bile salts in two groups of patients is being studied. Thus for patients with symptoms and findings compatible with bile gastritis have a higher concentration of bile acids than asymptomatic patients with incidental bile reflux. Deoxycholic acid seems to be more injurious to the gastric mucosa than cholic or chenic acids.