1. Department of Gastroenterology, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
2. Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
3. Department of Gastroenterology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
4. Obstetrical Department, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
5. Medical Diagnostic Center, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China