[1] Hatyai Hosp, Dept Internal Med, Div Gastroenterol, Songkhla, Thailand
[2] Hatyai Hosp, Dept Internal Med, Songkhla, Thailand
[3] Hatyai Hosp, Dept Internal Med, Div Hematol, Songkhla, Thailand
[4] Prince Songkla Univ, Songklanagarind Hosp, NKC Inst Gastroenterol & Hepatol, Fac Med, Hat Yai, Thailand
[5] Mahidol Univ, Siriraj Hosp, Siriraj GI Endoscopy Ctr, Dept Internal Med,Div Gastroenterol,Fac Med, Bangkok, Thailand
[6] Mahidol Univ, Siriraj Hosp, Dept Internal Med, Div Gastroenterol,Siriraj GI Endoscopy Ctr,Fac Med, Bangkok 10700, Thailand