Pelvic double-sphincter control complex. Theory of pelvic organ continence with clinical application.

A double-sphincter mechanism controlling the continence of pelvic organs is presented with a role-description of the involved pelvic musculature. The rectum and the urinary bladder identically have a detrusor with a neck related to a group of muscles which is responsible for its opening and closure. Whereas the levator ani and longitudinal muscle function to open the neck, the puborectalis and the internal sphincter are continent muscles. The puborectalis, not a part of the levator ani, gives origin to "individual" sphincters for each intrahiatal organ, and at the same time embraces all of them as their "common" sphincter. Thus, each intrahiatal organ is provided with a double voluntary sphincter apparatus consisting of "individual" and "common" sphincters. The mechanism of common sphincter, selective individual sphincter, and double-sphincter sphincter securative action is discussed. The external sphincter (anal and urethral) is an individual sphincter; the mechanism of its continent action is described. The different types of incontinence are outlined.