Is posterior compartment prolapse associated with anal incontinence?

Objective: It has been claimed that manifestations of posterior compartment prolapse, such as rectocele, enterocele and intussusception, are associated with anal incontinence (AI), but this has not been studied while controlling for anal sphincter trauma. We aimed to investigate this association in women with intact anal sphincter presenting with pelvic floor dysfunction.

Methods: This retrospective study analyzed 1133 women with intact anal sphincter presenting to a tertiary urogynecological center for pelvic floor dysfunction between 2014 and 2016. All women underwent a standardized interview, including assessment of symptoms of AI, clinical examination and three-/four-dimensional transperineal ultrasound. Descent of the rectal ampulla, true rectocele, enterocele, intussusception and anal sphincter trauma were diagnosed offline.

Results: Mean age was 54.1 (range, 17.6-89.7) years and mean body mass index was 29.4 (range, 14.7-67.8) kg/m . AI was reported by 149 (13%) patients, with a median St Mark's anal incontinence score of 12 (interquartile range, 1-23). Significant posterior compartment prolapse was seen in 693 (61%) women on clinical examination. Overall, 638 (56%) women had posterior compartment prolapse on imaging: 527 (47%) had a true rectocele, 89 (7.9%) had an enterocele and 26 (2.3%) had an intussusception. Women with ultrasound-diagnosed enterocele had a significantly higher rate of AI (23.6% vs 12.3%; odds ratio (OR), 2.21 (95% CI, 1.31-3.72); P = 0.002), but when adjusted for potential confounders, this association was no longer significant (OR, 1.56 (95% CI, 0.82-2.77); P = 0.134).

Conclusion: In women without anal sphincter trauma, posterior compartment prolapse, whether diagnosed clinically or by imaging, was not shown to be associated with AI. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.