Résumé : Up infection of the stomach is not a risk factor for reflux oesophagitis, and some studies suggest that Up may protect against reflux oesophagitis. There is an increased risk of reflux oesophagitis after Up eradication, there is a negative correlation between the presence of Up and the grade of reflux oesopliagitis, and there is a negative correlation between the prevalence of Up and of ocsophageal and cordial cancer. Several mechanisms could link Up and reflux, but until now, only hypotheses are available. The strongest candidate mechanisms for explaining the increased frequency of GERD after Up eradication are an increased gastric acid secretion in patients whom Up functionally impaired gastric acid secretion in through gastric body inflammation, and changes in life-style after Up eradication. Nothing is known about the influence of Up on TL ESRs, but speculation is open ; we also review the possible role ofsomatostatin, gastrin, prostaglandins and leukotrienes, EGF, and NO. More studies are needed to answer many of the raised questions.