1. Department of Medicine II, University Hospital Freiburg, Freiburg, Germany
2. Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
3. University Hospital Heidelberg, Heidelberg, Germany
4. Dept. of General and Visceral Surgery, Medical Center – University of Freiburg, Freiburg, Germany
5. Department of Gastroenterology, Eberhard-Karls-Universität Tübingen Medizinische Fakultät, Tübingen, Germany
6. Innere I, Uniklinik Ulm, Ulm, Germany