Major violations of anorectal fistula anal, very few involved in the rectum, so called anal fistula. Connected with the perineal area of the granulomatous skin tube mouth tooth more line is located near the mouth is located outside the perianal skin by the Office of the fistula wall thickening of fibrous tissue composed of a layer of granulation tissue within the complex, long poor, the incidence rate second only to hemorrhoids, was particularly prevalent in young and middle-aged men may be related to male sex hormones, one of the target organ of the sebaceous glands secrete strong.