ABSTRACT

The Musculoelastic Theory of anorectal function and dysfunction states “Anorectal dysfunction in the female is mainly caused by lax suspensory ligaments inactivating anorectal muscle forces”. Anorectal closure. The rectovaginal fascia inserts into perineal body, levator plate (LP) and the uterosacral ligaments . Contraction of levator plate stiffens rectovaginal fascia and both walls of rectum. Contraction of longitudinal muscle of the anus (LMA) against the uterosacral ligaments stretches the rectum around a contracted puborectalis muscle, to create the anorectal angle and closure. Defaecation. Puborectalis relaxes. Posteriorly acting LMA/LP vectors open out the anorectal angle; forward contraction of the pubococcygeus vector stiffens the perineal body, and anterior wall of anus; the rectum empties

Pathogenesis. Is similar to that described by the Integral Theory 1 for urinary incontinence: damaged ligaments decrease the force of opening and closure vectors. Surgery according to this theory. Reinforcement of damaged ligaments with precisely implanted polypropylene tapes restores structure and function.