1. Gastroenterology, Edouard Herriot Hospital, Lyon, France
2. Gastroenterology and Endoscopy Unit, University Hospital Centre Rennes, Rennes, France
3. Gastroenterology, University of Rome Tor Vergata Faculty of Medicine and Surgery, Rome, Italy
4. Gastroenterology and Endoscopy Unit, CHU Dupuytren Limoges, Limoges, France