[1] KEPCO Med Ctr, Dept Internal Med, Seoul, South Korea
[2] Kyung Hee Univ, Sch Med, Dept Internal Med, Div Gastroenterol, 23 Kyungheedae Ro, Seoul 130872, South Korea
[3] Korea Univ, Coll Med, Inst Digest Dis & Nutr, Dept Internal Med,Div Gastroenterol & Hepatol, Seoul, South Korea
[4] Dongguk Univ, Coll Med, Dept Internal Med, Gyeongju, South Korea
[5] Dongguk Univ, Grad Sch Med, Dept Internal Med, Goyang, South Korea
[6] Soonchunhyang Univ, Coll Med, Digest Dis Ctr, Dept Internal Med, Bucheon, South Korea
[7] Soonchunhyang Univ, Coll Med, Res Inst, Dept Internal Med, Bucheon, South Korea
[8] Catholic Univ Korea, Seoul St Marys Hosp, Coll Med, Dept Internal Med, Seoul, South Korea