1. Division of Gastroenterology, Department of Internal Medicine, Hallym University Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Korea
2. Division of Gastroenterology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
3. Division of Gastroenterology, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea
4. Division of Gastroenterology, Department of Internal Medicine, Hallym University Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, Korea
5. Division of Gastroenterology, Department of Internal Medicine, Gangdong Sacred Heart Hospital, Seoul, Korea
6. Department of Internal Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea