[1] Humanitas Univ, Dept Biomed Sci, I-20090 Rozzano, Italy
[2] Humanitas Clin & Res Ctr, Endoscopy Unit, IRCCS, I-20090 Rozzano, Italy
[3] Univ Oslo, Inst Hlth, Fac Med, Clin Effectiveness Res Grp, N-0315 Oslo, Norway
[4] Showa Univ, Digest Dis Ctr, Northern Yokohama Hosp, Yokohama 2240032, Japan
[5] Vet Affairs Med Ctr, Div Gastroenterol & Hepatol, Kansas City, MO 64128 USA