1. Department of Gastroenterology, Changhai HospitalThe Naval Medical University (Second Military Medical University) Shanghai China
2. Department of GastroenterologyShenzhen People's Hospital (Second Clinical Medical College of Jinan University Shenzhen, Guangdong Province China
3. Department of GastroenterologyThe General Hospital of Northern Theater Command Shenyang, Liaoning Province China
4. Department of GastroenterologyBeijing Friendship Hospital, Capital Medical University Beijing China