**9. Anorectal function, fecal incontinence and obstructive defecation**

The anecdotal observation that midurethral slings and repair of loose uterosacral ligaments can cure fecal incontinence has led Petros and Swash (2008) to establish a new theory of anorectal function. A new complex musculo-elastic sphincter mechanism was detected. Its mechanism is similar to that of bladder neck closure. Directional muscle forces stretch the rectum backwards and downwards around an anus firmly anchored by the puborectalis muscle. Anorectal closure occurs when the backward muscle forces of LP and LMA stretch the rectum around the anus, which is anchored by PRM-contraction. Upon comparing Figure 3b with Figure 3a, the rectum above the anal canal has been markedly angulated (and closed) by muscle actions during effort. Upon relaxation of PRM, LP/LMA vectors open out the anal canal for evacuation (broken lines, Fig2)

Fecal incontinence can occur when connective tissue at the anterior zone is loose. Then the insertion points of the puborectalis muscle are dislocated and the muscle is weak. Furthermore, the anterior insertion points of the levator plate are loose and the muscle is weak and the anorectal closure is weak, also.

When connective tissue at the posterior zone is loose, the muscles also cannot act optimally and fecal incontinence can occur. Lax uterosacral ligaments can explain rectal intussusception and obstructive defecation. The levator plate cannot tension the rectovaginal fascia. The perineal body is an important anchoring point and, if loose, it can contribute to fecal incontinence and obstructive defecation (Petros 2010, Abendstein and Petros 2008).
