1. Department of Medicine B (Gastroenterology, Hepatology, Endocrinology, Clinical Infectiology), University Hospital Muenster, Muenster, Germany
2. Department of Gastroenterology, St. Barbara-Klinik Hamm-Heessen, Hamm, Germany
3. Department for Internal Medicine, Raphaelsklinik Muenster, Muenster, Germany
4. Department of Gastroenterology, Hepatology and Transplant Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany