**2. Preoperative setting: diagnostic esophago-gastro-duodenoscopy**

In "The clinical practice guidelines of the EAES on bariatric surgery: update 2020" the indication of a pre-operative EGD has been approved [1]. Clinically significant gastrointestinal (GI) symptoms should be evaluated before bariatric procedures with imaging studies, upper GI series, or endoscopy. All patients who where enrolled for a sleeve gastrectomy have to be examined with a gastroscopy for presence of hiatal hernia and esophageal reflux. Endoscopists have to look for signs of GERD. This diagnosis is a contraindication for a sleeve gastrectomy. Presence of hiatal hernia is also important from the surgical point of view, as it also needs to be repaired while bariatric surgery. In the diagnostic gastroscopy Helicobacterpylorii diagnosis has to been established. Recent studies illustrate a relationship of Helicobacter pylori with the occurrence of marginal ulcers postoperatively especially following RYGB.
