[1] Chung Ang Univ Hosp, Dept Gastroenterol, Seoul, South Korea
[2] Sungkyunkwan Univ, Samsung Med Ctr, Dept Med, Sch Med, Seoul, South Korea
[3] Catholic Univ Korea, Daejeon St Marys Hosp, Dept Internal Med, Div Gastroenterol, Daejeon, South Korea
[4] Catholic Univ Korea, St Vincents Hosp, Dept Internal Med, Coll Med, Suwon, South Korea
[5] Korea Univ, Coll Med, Ansan, South Korea
[6] Soonchunhyang Univ, Dept Internal Med, Coll Med, Cheonan, South Korea
[7] Korea Univ, Dept Internal Med, Coll Med, Seoul, South Korea
[8] Seoul Natl Univ, Dept Internal Med, Bundang Hosp, Seongnam, South Korea
[9] Pusan Natl Univ, Yangsan Hosp, Dept Internal Med, Coll Med, Yangsan, South Korea
[10] Dongguk Univ, Ilsan Hosp, Dept Internal Med, Goyang, South Korea
[11] Kyungpook Natl Univ, Sch Med, Dept Internal Med, Daegu, South Korea
[12] Keimyung Univ, Sch Med, Dept Internal Med, Daegu, South Korea
[13] Chosun Univ, Sch Med, Dept Internal Med, Gwangju, South Korea
[14] Kyung Hee Univ, Sch Med, Dept Internal Med, Seoul, South Korea
[15] Chung Ang Univ, Gwangmyeong Hosp, Dept Internal Med, Gwangmyeong, South Korea
[16] Chung Ang Univ Hosp, Dept Internal Med, Seoul, South Korea