1. Department of Clinical Laboratory, The Sixth Affiliated Hospital Sun Yat‐sen University Guangzhou China
2. Guangdong Institute of Gastroenterology 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
4. Department of Colorectal Surgery, The Sixth Affiliated Hospital Sun Yat‐sen University Guangzhou Guangdong China