1. Interdisciplinary Crohn Colitis Centre Rhein-Main, Frankfurt/Main, Germany
2. Department of Gastroenterology and Clinical Nutrition, DGD Clinics Sachsenhausen, Frankfurt/Main, Germany
3. Hacettepe University, Faculty of Health Sciences, Ankara, Turkey
4. Gastroenterological Practice, Cottbus, Germany
5. Department of Medical Affairs, Vifor Pharma, Munich, Germany
6. Department of Gastroenterology, Agaplesion Markus Hospital, Frankfurt/Main, Germany