1. Gastroenterology Unit, Ospedale Valduce, Como, Italy
2. Digestive Endoscopy Unit, Catholic University of Rome, Rome, Italy
3. Digestive Endoscopy Unit, Fondazione Poliambulanza, Brescia, Italy
4. Division of Gastroenterology, Shaare Zedek Medical Center, Jerusalem, Israel
5. Department of Medicine II, Sana Klinikum, Offenbach, Germany
6. Royal Free Unit for Endoscopy, Centre for Gastroenterology, The Royal Free Hospital & University College London, London, UK
7. Endoscopy Unit, The Royal Infirmary of Edinburgh, Scotland, UK
8. Department of Gastroenterology, South Tyneside Hospital, South Shields, UK
9. Department of Medicine B, University of Münster, Münster, Germany
10. Department of Gastroenterology, Hospital de Navarra, Pamplona, Spain
11. Department of Gastroenterology and Digestive Endoscopy, Georges Pompidou European Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
12. Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, Netherlands
13. Endoscopy Unit, Nuovo Regina Margherita Hospital, Rome, Italy
14. Division of Gastroenterology U, Azienda Ospedaliero-Universitaria, Città della Salute e della Scienza, Turin, Italy