The main manifestation symptoms of anal sphincter injury are divided into the following points: a. Anal sphincter injury decreases the control ability of the anal canal. The anal sphincter is an important tissue that controls anal closure, and if its function is impaired it will affect normal anal closure, resulting in the inability to defecate independently, the phenomenon of fluid leakage when there is no sense of defecation, and in serious cases, even the phenomenon of stool leakage. Second, the anal sphincter is damaged, resulting in a decrease in the protective function of the inner side of the anus. The anal sphincter is the most important and last line of defense at the end of the rectum, once damaged external bacteria or viruses will take advantage of the situation, leading to inflammatory lesions inside the rectum, and even leading to perianal disease. Third, in addition to the anal sphincter injury will also show the anal area pain symptoms.