[1] Univ Hosp Geneva, Serv Gastroenterol & Hepatol, CH-1211 Geneva 14, Switzerland
[2] SMAD, Dept Digest Dis, Rennes, France
[3] Hop Univ Erasme, Dept Gastroenterol & Hepatopancreatol, Brussels, Belgium
[4] Policlin A Gemelli, Digest Endoscopy Unit, Rome, Italy
[5] ESGENA, Ulm, Germany
[6] Ruhr Univ Bochum, Dept Med, Bochum, Germany