[1] We Comfortable Clin, Dept Internal Med, Seoul, South Korea
[2] Kangwon Natl Univ, Dept Internal Med, Sch Med, Chunchon, South Korea
[3] Korea Univ, Dept Internal Med, Div Gastroenterol & Hepatol, Coll Med, 73 Goryeodae Ro, Seoul 02841, South Korea
[4] Hanyang Univ, Hanyang Univ Hosp, Dept Internal Med, Div Gastroenterol,Coll Med, 222 Wangsimni Ro, Seoul 04763, South Korea
[5] Hanyang Univ, Coll Med, Dept Internal Med, Guri Hosp, Guri, South Korea
[6] Gachon Univ, Dept Internal Med, Div Gastroenterol, Gil Med Ctr, Incheon, South Korea
[7] Univ Ulsan, Asan Med Ctr, Dept Gastroenterol, Coll Med, Seoul, South Korea
[8] Kyung Hee Univ, Dept Internal Med, Div Gastroenterol & Hepatol, Sch Med, Seoul, South Korea
[9] Sungkyunkwan Univ, Kangbuk Samsung Hosp, Dept Internal Med, Sch Med, Seoul, South Korea
[10] Catholic Univ Korea, Coll Med, Dept Internal Med, Eunpyeong St Marys Hosp, Seoul, South Korea