[1] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Gastroenterol, Seoul, South Korea
[2] Kyungpook Natl Univ, Dept Internal Med, Sch Med, Daegu, South Korea
[3] Yeungnam Univ, Coll Med, Dept Internal Med, Daegu, South Korea
[4] Daegu Catholic Univ, Sch Med, Dept Internal Med, Daegu, South Korea
[5] Univ Ulsan, Coll Med, Asan Med Ctr, Inflammatory Bowel Dis Ctr, Seoul, South Korea