1. Clinic for Internal Medicine IV (Gastroenterology, Hepatology and Infectious Diseases), Jena University Hospital, Jena, Germany;
2. Department of Interdisciplinary Endoscopy, University Hospital Hamburg-Eppendorf, Hamburg, Germany;
3. Division of Gastroenterology and Hepatology, Centre Hospitalier Universitaire Vaudois/CHUV, Lausanne, Switzerland;
4. Clinic for General, Visceral und Vascular Surgery, Jena University Hospital, Jena, Germany;
5. Department of Gastoenterology, Hepatology, Endocrinology, Diabetology and Infectiology, Clinic Fulda, Fulda, Germany