1. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo , Norway
2. Department of Gastroenterology, Østfold Hospital Trust , Sarpsborg , Norway
3. Research and Development Department, Vestfold Hospital Trust , Tønsberg , Norway
4. Department of Gastroenterology, Oslo University Hospital , Oslo , Norway
5. Institute of Health and Society, Faculty of Medicine, University of Oslo , Oslo , Norway
6. Department of Health Sciences, Østfold University College , Halden , Norway
7. Department of Gastroenterology, Telemark Hospital Trust , Skien , Norway
8. Unger-Vetlesen Institute, Lovisenberg Diaconal Hospital , Oslo , Norway
9. Department of Gastroenterology, Lovisenberg Diaconal Hospital , Oslo , Norway
10. Pediatric Department, Oslo University Hospital , Oslo , Norway
11. Department of Medicine, Vestfold Hospital Trust , Tønsberg , Norway
12. Department of Medicine, Diakonhjemmet Hospital , Oslo , Norway
13. Department of Gastroenterology, Akershus University Hospital , Lørenskog , Norway
14. Department of Medicine, Vestre Viken Hospital Trust , Bærum , Norway
15. Department of Medicine, Innlandet Hospital Trust , Gjøvik , Norway
16. Faculty of Health Sciences, Oslo Metropolitan University , Oslo , Norway