Is perineal hypermobility an independent predictor of obstructive defecation?

Symptoms of obstructed defecation (OD) and anatomical abnormalities of the posterior compartment are prevalent in urogynecological patients. The aim of this study was to determine whether perineal hypermobility is an independent predictor of OD, as is the case for rectocele, enterocele and rectal intussusception.

This is a retrospective study of 2447 women attending a tertiary urodynamic center between September 2011 and December 2016. The assessment included a structured interview, urodynamic testing, a clinical examination and 4D transperineal ultrasound. After exclusion of previous pelvic floor surgery and defined anatomical abnormalities of the anorectum, 796 patients were left for analysis. Perineal hypermobility was defined as rectal descent ≥ 15 mm below the symphysis pubis, determined in stored ultrasound volume datasets offline, using proprietary software, blinded to all other data. Any association between perineal hypermobility and symptoms of obstructed defecation was tested for by chi-square (X²) test.

For the 796 patients analyzed, median age was 52 (range, 16-88) years with a mean BMI of 27 (range, 15-64) kg/m². Average vaginal parity was two (range, 0-8). Reported OD symptoms in this group included sensation of incomplete emptying in 335 (42%), straining at stool in 300 (37%) and digitation in 83 (10%). At least one of those symptoms was reported by 424 (53%) women; 153 showed perineal hypermobility. There was no significant association between perineal hypermobility and OD symptoms on univariate testing.

We found no evidence of an independent association between perineal hypermobility and obstructed defecation.