1. Department of Gastroenterology, Telemark Hospital, Skien, Norway;
2. Department of Gastroenterology, Oslo University Hospital Ullevål, Oslo, Norway;
3. Department of Gastroenterology, Østfold Hospital Trust, Østfold University College, Fredriksstad, Grålum, Norway;
4. Department of Gastroenterology, Oslo University Hospital Ullevål, and Institute of Health and Society, Faculty of Medicine, University of Oslo, Oslo, Norway;
5. Department of Gastroenterology, Østfold Hospital Trust, Grålum, Norway;
6. Department of Gastroenterology, Sørlandet Hospital, Arendal, Norway;
7. Department of Gastroenterology, Innlandet Hospital Trust, Brumunddal, Norway;
8. Department of Gastroenterology, Akershus University Hospital, and Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway;
9. Department of Research and Development, Telemark Hospital, and Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway;
10. Department of Gastroenterology, Oslo University Hospital Ullevål, and Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway;
11. Department of Research and Development, Vestfold Hospital, and Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway