[1] Univ Padua, Dept Surg Oncol & Gastroenterol Sci, Padua, Italy
[2] Univ Genoa, Dept Internal Med, I-16126 Genoa, Italy
[3] Univ Milan, Milan, Italy
[4] Osped Maggiore Policlin Sci Med, Fdn IRCCS Ca Granda, Milan, Italy
[5] Johns Hopkins Univ, Div Gastroenterol, Baltimore, MD USA
[6] St Andre Hosp, Dept Gastroenterol, Bordeaux, France
[7] Izmir Training & Res Hosp, Izmir, Turkey