[1] Indiana Univ, Sch Med, Div Gastroenterol Hepatol, 550 North Univ Blvd,IU Hosp 4100, Indianapolis, IN 46202 USA
[2] Stanford Univ, Sch Med, Div Gastroenterol & Hepatol, Stanford, CA USA
[3] Dept Vet Affairs Med Ctr, White River Jct, VT USA
[4] Geisel Sch Med Dartmouth, Div Gastroenterol & Hepatol, New Hampshire, Hanover, Jamaica
[5] Univ Connecticut, Sch Med, Div Gastroenterol & Hepatol, Farmington, CT USA
[6] New York Univ, New York Harbor Vet Affairs Med Ctr, Grossman Sch Med, New York, NY USA
[7] Geisel Sch Med Dartmouth, Dartmouth Hitchcock Med Ctr, Div Gastroenterol & Hepatol, Hanover, NH USA
[8] Vet Hlth Adm, Natl Gastroenterol & Hepatol Program, Washington, DC USA
[9] Univ Washington, Sch Med, Dept Med, Div Gastroenterol, Seattle, WA USA
[10] Vet Affairs San Francisco Healthcare Syst, San Francisco, CA USA
[11] Univ Calif San Francisco, Dept Med, Div Gastroenterol, San Francisco, CA USA
[12] Kaiser Permanente Div Res, Oakland, CA USA
[13] Humanitas Univ, Dept Biomed Sci, Pieve Emanuele, Italy
[14] Human Clin & Res Ctr Ist Ricovero & Cura Caratter, Endoscopy Unit, Milan, Italy