[1] Dudley Grp Hosp, Dept Gastroenterol, Pensnett Rd, Dudley DY1 2HQ, England
[2] Birmingham City Univ, Birmingham, W Midlands, England
[3] St Georges Univ, True Blue, Grenada
[4] IRCCS Policlin San Donato, Gastroenterol & Digest Endoscopy Unit, San Donato Milanese, Italy
[5] St Marienkrankenhaus Frankfurt, Dept Internal Med & Gastroenterol, Frankfurt, Germany
[6] NYU, Langone Med Ctr, Div Gastroenterol, New York, NY USA
[7] Univ Hosp Mainz, Intervent Endoscopy Ctr, Mainz, Germany