150 years after Beaumont duodenogastric reflux is still under discussion. The cytotoxic effect of bile acids and lysolecithin is proved experimentally, its clinical role, however is called in question. Whereas a pathogenetic role is demonstrated in stress ulcer formation, its role in chronic ulcer is still questionable. Whereas its role in secondary alkaline reflux oesophagitis can be shown clinically and experimentally, the function of duodenogastric reflux in primary reflux oesophagitis still remains to be elucidated. The question of duodenogastric reflux in the operated stomach is even more difficult. A deleterious effect is discussed by some authors however it is not proved clinically. There is no doubt about the effect of intestino-gastric reflux against stomal ulceration in gastro-jejunal reconstruction after gastrectomy.