[1] Natl Taiwan Univ Hosp, Dept Internal Med, Taipei 100, Taiwan
[2] Natl Taiwan Univ Hosp, Dept Pathol, Taipei 100, Taiwan
[3] Natl Taiwan Univ, Bei Hu Branch, Dept Internal Med, Taipei 10764, Taiwan
[4] Digest Endoscopy Soc Taiwan, Colonoscopy Qual Assurance Working Grp, Taipei, Taiwan