1. Department of Gastroenterology, Hospital Asklepios Klinikum Schwalmstadt, Krankenhausstraße 27, 34613 Schwalmstadt, Germany
2. Department of Gastroenterology, University Hospital Berne, Freiburgstrasse 18, 3010 Bern, Switzerland
3. Department of Medicine, Hospital Knappschaftsklinikum Saar, In d. Humes 35, 66346 Püttlingen, Germany
4. Department of Medicine II, Saarland University Medical Center, Saarland University, 66421 Homburg, Germany