The rectovaginal septum (rectovaginal fascia, Denonvilliers fascia in females) is the condensed connective tissue layer between the posterior vaginal wall and the anterior rectal wall, extending from the perineal body inferiorly to the peritoneal reflection (Pouch of Douglas) superiorly. It provides structural support to the posterior vaginal wall and separates the rectum from the vagina.
Separates the posterior vaginal wall from the anterior rectum, prevents rectocele formation by supporting the posterior vaginal wall, and defines the surgical plane for posterior vaginal repair and rectovaginal fistula closure.
Disruption or attenuation of the rectovaginal septum produces a posterior vaginal wall prolapse (rectocele), where the rectum bulges anteriorly through the thinned vaginal wall. Posterior colporrhaphy plicates the pararectal fascia to restore posterior wall support. Rectovaginal fistula repair requires dissection in the rectovaginal septum plane to allow tension-free flap closure. In abdominoperineal resection, the rectovaginal septum plane is the surgical dissection plane to separate the anterior rectal mesentery from the posterior vagina.
Attenuation of the rectovaginal septum from childbirth, chronic straining, or connective tissue laxity produces a posterior vaginal wall prolapse (rectocele) with anterior rectal bulging into the vaginal canal causing a feeling of incomplete evacuation; managed by posterior colporrhaphy with or without levator plication.
