1. Internal Medicine, Protestant Hospital , Cologne , Germany
2. Department of Internal Medicine, Interdisciplinary Crohn Colitis Centre , Minden , Germany
3. Clinic of General Internal Medicine I, University Hospital Schleswig-Holstein , Campus Kiel, Kiel , Germany
4. Gastroenterology Practice , Kiel-Altenholz , Germany
5. Gastroenterology Practice Clinic , Nuremberg , Germany
6. Gastroenterology Practice , Berlin , Germany
7. Department of Internal Medicine , Ferring Arzneimittel GmbH, Kiel , Germany
8. Department of Internal Medicine , St. Bernward Hospital, Hildesheim , Germany