[1] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Gastroenterol, Seoul, South Korea
[2] Yang Hosp, Dept Surg, Seoul, South Korea
[3] Seoul Song Colorectal Hosp, Digest Endoscop Ctr, Seoul, South Korea
[4] Hansol Hosp, Dept Internal Med, Seoul, South Korea
[5] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Med, Seoul, South Korea
[6] Hallym Univ, Coll Med, Kangdong Sacred Heart Hosp, Dept Internal Med, Chunchon, South Korea
[7] Kyung Hee Univ, Coll Med, Kyung Hee Univ Hosp Gangdong, Dept Internal Med, Seoul, South Korea
[8] Kangdong Seoul Colon & Rectal Surg, Seoul, South Korea
[9] Daehang Hosp, Dept Gastroenterol, Seoul, South Korea
[10] Seoul Natl Univ, Coll Med, Dept Internal Med, Seoul, South Korea
[11] Seoul Natl Univ, Coll Med, Liver Res Inst, Seoul, South Korea
[12] Seoul Natl Univ, Bundang Hosp, Dept Internal Med, Seongnam, South Korea
[13] VHS Med Ctr, Dept Internal Med, Seoul, South Korea
[14] Konkuk Univ, Sch Med, Med Ctr, Dept Internal Med, Seoul, South Korea
[15] Natl Police Hosp, Dept Internal Med, Seoul, South Korea
[16] Jamsil Seoul Surg Clin, Seoul, South Korea