Department of Gastroenterology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden. Department of Gastroenterology, Karolinska Institutet, Danderyd Hospital, Sweden. Department of Medicine, Karolinska Institutet, Stockholm, Sweden. Department of Medicine, Karolinska Institutet, Stockholm, Sweden. Department of Gastroenterology, Karolinska Institutet, Danderyd Hospital, Sweden. ITH, Karolinska University Hospital, Stockholm, Sweden. ITH, Karolinska University Hospital, Stockholm, Sweden. Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden. ITH, Karolinska University Hospital, Stockholm, Sweden. Department of Medicine, Karolinska Institutet, Stockholm, Sweden.