1. Department of Otolaryngology Head and Neck Surgery, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, Sun Yat-Sen University, Guangzhou, Guangdong, China
2. Department of Gastrointestinal Endoscopy, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
3. Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China