Division of Medical Gastroenterology, Department of Internal Medicine, Sahlgrenska University Hospital, Blå Stråket 3, 413 35, Gothenburg, Sweden. per.hedenstrom@vgregion.se. Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. per.hedenstrom@vgregion.se. Department of Clinical Pathology and Genetics, Sahlgrenska University Hospital, Gothenburg, Sweden. Division of Medical Gastroenterology, Department of Internal Medicine, Sahlgrenska University Hospital, Blå Stråket 3, 413 35, Gothenburg, Sweden. Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. Department of Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden.