The muscles surrounding the anus include the anal sphincter, the anal retinaculum, the puborectalis, the longitudinal muscles of the joint, and the rectal ring muscles. The anal sphincter consists of the internal and external sphincters, with the internal sphincter consisting of the superficial and deep internal sphincter and the external sphincter consisting of the subcutaneous, deep, and anterior external sphincter, which are the muscles that control anal contraction. In the anal canal there is a control of anal contraction of the tissue called the anorectal ring, it is by the anal sphincter, sphincter, the anal muscle and the rectal ring muscle, composed of a ring muscle group, if the operation cut off the anorectal ring will be anal incontinence, it is the main role is to control the contraction of the anus. In addition, the anorectalis muscle can be divided into pubococcygeus muscle, iliococcygeus muscle, puborectalis muscle was U-shaped distribution, encircling the end of the rectum, upward extension of the formation of the rectal ring muscle, the joint longitudinal muscle traveled in the internal sphincter between the anal canal is also encircling the anal canal stops at the skin.