In males the muscle inserts with the fascia of the levator ani to either side of the rectum or to other fascial elements of the pelvic diaphragm.

In females the rectococcygeal muscle additionally runs around the sides of the rectum to connect to the rectovaginal fascia of the posterior vaginal wall.

[1] The rectoccygeal muscles are innervated by autonomic nerves associated with the inferior hypogastric plexus.

The rectococcygeal muscle acts to lift the sphincter, thereby effectively shortening the rectum and aiding evacuation.

[8][9] This article incorporates text in the public domain from page 1186 of the 20th edition of Gray's Anatomy (1918)