1. Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
2. Department of Visceral Surgery and Medicine, Inselspital Bern University Hospital, University of Bern, Bern, Switzerland
3. Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, SwitzerlandDepartment of Visceral Surgery and Medicine, Inselspital Bern University Hospital, University of Bern, Bern, Switzerland
4. Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland
5. Center of Gastroenterology and Hepatology, Zurich, Switzerland
6. Department of Gastroenterology and Hepatology, University Medical Clinic, Kantonsspital Baselland, Liestal, Switzerland
7. Department of Gastroenterology, Kantonsspital Nidwalden, Stans, Switzerland
8. Service of Gastroenterology and Hepatology, Lausanne University Hospital, Lausanne, Switzerland; Crohn and Colitis Center, Gastroentérologie Beaulieu SA, Lausanne, Switzerland
9. Department of Gastroenterology, Kantonsspital Münsterlingen, Münsterlingen, Switzerland
10. Department of Gastroenterology and Hepatology, Kantonsspital St. Gallen, St. Gallen, Switzerland
11. Department of Visceral Surgery and Medicine, Inselspital Bern University Hospital, University of Bern, Freiburgstr. 18, 3010 Bern, Switzerland