Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark. Clinical Institute, Aalborg University, Aalborg, Denmark. Gastrounit, Hvidovre University Hospital, Hvidovre, Denmark. Copenhagen University Hospital/Herlev, Copenhagen, Denmark. Abdominalcenter K, Bispebjerg Hospital, Copenhagen, Denmark. Department of Clinical Medicine, University of Bergen, Bergen, Norway. Department of Medicine, Haukeland University Hospital, Bergen, Norway. Pediatric Department, Haukeland University Hospital, Bergen, Norway. Center for Diabetes Research, University of Bergen, Bergen, Norway. Department of Surgery, Oslo University Hospital, Oslo, Norway. Department of Gastroenterology, Oslo University Hospital, Oslo, Norway. Faculty of Medicine, University of Oslo, Oslo, Norway. Centre for Digestive Diseases, Karolinska University Hospital, Stockholm, Sweden. Department of Surgery, Lithuanian University of Health Sciences, Kaunas, Lithuania. Centre of Gastroenterology, Hepatology and Nutrition, Pauls Stradins Clinical University Hospital, Riga, Latvia. Chair of Internal Diseases Propedeutics, IM Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia. Department of Gastroenterology and Alimentary Tract Surgery, Tampere University Hospital, Tampere, Finland. Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.