puborektalis

The puborektalis muscle is a broad, sling-like muscle that originates from the pubic symphysis. It loops around the rectum and attaches to the anococcygeal ligament, which is a fibrous band extending from the coccyx to the anus. Together with the pubococcygeus muscle, it forms the puborectalis sling, a crucial component of the pelvic floor musculature.

This sling plays a vital role in fecal continence. When relaxed, it allows the rectum to straighten, facilitating defecation. During defecation, the puborectalis muscle relaxes, and the angle between the rectum and anus (the anorectal angle) increases, allowing for the passage of stool. Conversely, when contracted, the puborectalis muscle pulls the rectum forward and creates a sharp angle at the anorectal junction. This angle helps to maintain fecal continence by occluding the rectal lumen.

Dysfunction of the puborectalis muscle can lead to various issues, including constipation, fecal incontinence, and pelvic pain. Weakness or damage to this muscle can impair the ability to maintain continence. Conversely, excessive tightness or hypertonicity can make defecation difficult and contribute to straining. Physiotherapy, particularly pelvic floor exercises, is often used to address puborectalis muscle dysfunction. Understanding the anatomy and function of the puborectalis muscle is important for comprehending the mechanics of defecation and fecal continence.