1. Department of Gastroenterology, Hepatology and Gastrointestinal Oncology, Bogenhausen Academic Teaching Hospital, Technical University of Munich, Munich, Germany
2. Department of Internal Medicine – Division of Gastroenterology, Diabetology and Endocrinology, Kemperhof Koblenz, Koblenz, Germany
3. Department of Gastroenterology, Hepatology and Gastrointestinal Oncology, Isar Klinik, Munich, Germany
4. Helios Klinik Attendorn, Attendorn, Germany