1. Department of Gastroenterology and Endoscopy, Edouard Herriot Hospital, Lyon, France
2. Department of Gastroenterology and Endoscopy, Pontchaillou University Hospital, Rennes, France
3. Department of Gastroenterology and Endoscopy, Dupuytren University Hospital, Limoges, France
4. Department of Gastroenterology and Endoscopy, Saint Antoine Hospital, Paris, France
5. Department of Gastroenterology and Endoscopy, Amiens University Hospital, Amiens, France
6. Service de Biostatistique, Hospices Civils de Lyon, Lyon, France