Rectal Ampulla of the Male Right Colon, Lateral View

Description

Oriented in right lateral view, the male rectum is shown expanding into the rectal ampulla, the terminal dilatation that sits immediately superior to the pelvic floor and inferior to the sigmoid colon. The ampulla occupies the posterior pelvic compartment, with its convex anterior wall facing the prostate and posterior surface related to the sacrum and coccyx across the mesorectal fat. Inferiorly, the ampulla tapers toward the anal canal at the level of the anorectal junction, where the puborectalis sling creates the anorectal angle. A reservoir segment. That anatomic widening matters because it is where stool is temporarily stored before defecation, and its distension is what drives the rectoanal inhibitory reflex and the urge-to-defecate sensation. The right lateral perspective clarifies the relationship between the rectal dome (superior ampullary contour), the pelvic floor, and the anterior urogenital organs, which is the axis you think along during digital rectal examination and when planning low anterior resection or total mesorectal excision. It also helps explain why fecal impaction and rectal dilation can worsen outlet obstruction when the puborectalis fails to relax (dyssynergic defecation). Use this illustration in colorectal surgery teaching, pelvic anatomy labs, and physiology modules on continence and defecation, and as a publication figure when describing rectal reservoir function or the surgical planes around the mesorectum in male patients. It also supports patient-facing education materials for constipation, fecal impaction, and postoperative bowel habit changes after rectal cancer surgery. Anatomical accuracy verified by SciePro's Medical Advisory Board.