Rectal Plexus, Posterior View

Description

Posteriorly, the descending colon continues inferiorly as the rectum, with haustra fading as the bowel transitions from colon to the thicker-walled rectal ampulla. A nerve network hugs the posterolateral rectal wall, where parasympathetic pelvic splanchnic nerves (S2 to S4) mingle with sympathetic fibers arriving via the hypogastric nerves and inferior hypogastric plexus to form the rectal plexus. Blue venous channels parallel the neural meshwork along the rectum, and clustered lymph nodes track along the mesocolic and pararectal drainage pathways. Spatially, the plexus lies lateral to the rectal lumen, medial to the pelvic sidewall, and inferior to the sigmoid-descending junction. This posterior perspective matters when you need to teach or plan around autonomic injury in pelvic surgery. Total mesorectal excision and low anterior resection place the hypogastric nerves and pelvic splanchnic contributions at risk along the posterior and lateral mesorectum, and disruption can lead to postoperative constipation, impaired rectal sensation, and sexual dysfunction in men. Clear relationships between the rectal plexus and the accompanying rectal venous network also support discussions of internal hemorrhoids and portal-systemic anastomoses in the anorectal region. Use this illustration in pelvic anatomy blocks, colorectal surgery teaching files, and journal figures explaining defecatory reflex arcs and autonomic pathways to the hindgut. It also fits patient-facing education on nerve-sparing rectal cancer surgery when you need a clean posterior map of where the nerves travel. Anatomical accuracy verified by SciePro's Medical Advisory Board.