There are many causes of anal leakage, mainly referring to various causes of anal autonomic control disorders, which cannot control stool at will. The main reasons are: first, damage to the anorectal ring, such as anorectal surgery, if the anorectal ring is cut off will lead to the loss of the function of the anal sphincter, which will lead to anal leakage of feces due to sphincter relaxation. Second, if long-term severe prolapse or internal hemorrhoids prolapse, it will cause the anal sphincter muscle fatigue leading to relaxation, and poor anal closure during defecation will lead to anal leakage of feces. Third, anal surgery, if too much skin and surrounding tissues of the anal canal are removed, the formation of deeper scarring will also lead to incomplete anal closure. Fourth, damage to the central nervous system, spinal nerves or perineal nerves can cause the nerves innervating the anus to lose their normal function, resulting in the anal sphincter not being able to contract and relax at will, thus causing anal leakage.