Division of Gastroenterology, Department of Medicine, Haukeland University Hospital , Bergen , Norway. Norwegian Competence Center for Functional Gastrointestinal Disorders, Section of Gastroenterology, Department of Medicine, Haukeland University Hospital , Bergen , Norway. Center for Nutrition, Department of Clinical Medicine, University of Bergen , Bergen , Norway. Norwegian PSC Research Center and Section of Gastroenterology and Research Institute of Internal Medicine, Oslo University Hospital and University of Oslo , Oslo , Norway. Unger-Vetlesen Institute, Lovisenberg Diaconal Hospital , Oslo , Norway. Division of Gastroenterology, Department of Medicine, Stord Hospital, Helse-Fonna , Stord , Norway.