1. Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
2. First Clinical Medical College of Nanjing Medical University, Nanjing, China
3. Department of Gastroenterology, People's Hospital of Jingjiang, Taizhou, China
4. Department of Gastroenterology, First Affiliated Hospital of Soochow University, Suzhou, China