Puborectalis forms a U-shaped sling around the anorectal junction, creating the anorectal angle (normally 90 degrees) that is the primary structural mechanism of faecal continence. During defaecation, it must relax to straighten the anorectal angle.
| Origin | Pubic bone — posterior surface, on both sides |
|---|---|
| Insertion | Loops behind the anorectal junction — no bony insertion, forms a muscular sling |
| Nerve Supply | Pudendal nerve and direct sacral nerve branches (S3, S4) |
| Blood Supply | Internal pudendal artery |
| Actions | Maintains the anorectal angle — the primary continence mechanism; Creates the 90-degree angle between rectum and anal canal that prevents faecal leakage; Paradoxically contracts during straining to resist defaecation |
|---|
Puborectalis dyssynergia (non-relaxing puborectalis) produces obstructed defaecation — the muscle fails to relax during straining, preventing the anorectal angle from opening. Biofeedback therapy retrains puborectalis relaxation. In cases of faecal incontinence, the puborectalis sling can be augmented by sacral nerve stimulation. MRI defaecography assesses puborectalis function dynamically.
Assessed by digital rectal examination (the puborectalis sling is palpated as a posterior ledge) and by MRI defaecography.
Non-relaxing puborectalis producing obstructed defaecation syndrome with straining and incomplete evacuation, managed by biofeedback therapy for paradoxical puborectalis contraction.
This website uses cookies to enhance your experience. Some are essential for site functionality, while others help us analyze and improve your usage experience. Please review your options and make your choice.
If you are under 16 years old, please ensure that you have received consent from your parent or guardian for any non-essential cookies.
Your privacy is important to us. You can adjust your cookie settings at any time. For more information about how we use data, please read our privacy policy. You may change your preferences at any time by clicking on the settings button below.
Note that if you choose to disable some types of cookies, it may impact your experience of the site and the services we are able to offer.
Some required resources have been blocked, which can affect third-party services and may cause the site to not function properly.
This website uses cookies to enhance your browsing experience and ensure the site functions properly. By continuing to use this site, you acknowledge and accept our use of cookies.
