1. The Sixth Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Disease, Guangzhou, People’s Republic of China
2. Fujian Medical University Union Hospital, Fuzhou, People's Republic of China
3. School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China
4. Xinhua Hospital, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
5. Xiehe Hospital, Huazhong University of Science and Technology, Wuhan, China
6. The First People’s Hospital, Guangzhou City, People’s Republic of China
7. The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, People’s Republic of China
8. The First People’s Hospital, Foshan City, People’s Republic of China
9. Zhujiang Hospital, Nanfang University of Medical Science, Guangzhou, People’s Republic of China
10. Guangdong Provincial Peoples Hospital, Guangzhou, People’s Republic of China
11. Ruijin Hospital, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
12. General Hospital, Hunan Province, Changsha, People’s Republic of China
13. The First Affiliated Hospital, Xiamen University, Xiamen, People’s Republic of China
14. Guangzhou General Hospital of Guangzhou Military Command, Guangzhou, People’s Republic of China
15. The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, People’s Republic of China
16. Xinhua Hospital, Dongguan, People’s Republic of China