Regurgitation of duodenal juice into the stomach is generally accepted to have a damaging effect on gastric mucosa. It may cause endoscopically visible irritation and microscopically detected superficial inflammation. Some years after cholecystectomy this reflux disease of the gastric mucosa is significantly more frequently observed than in persons who have normally concentrating gall bladder. The possible role of a gall bladder as bile reservoir is discussed concerning the pathogenesis of reflux gastritis.