Rectal intussusception is associated with abnormal levator ani muscle structure and morphometry

Anorectal symptoms are common in urogynaecological patients, and so are anatomical abnormalities of the anorectum associated with such symptoms. One such abnormality is rectal intussusception (RI). The aim of this retrospective study was to determine the prevalence of RI in a tertiary urogynaecological population and to describe the associated symptoms, signs and ultrasound findings, in particular those relating to pelvic floor function and anatomy. It was hypothesized that RI is associated with abnormal levator ani muscle anatomy and function.

The electronic records and volume imaging datasets of 967 women who presented to a tertiary urogynaecological clinic between May 2005 and March 2009 were analysed. Rectal intussusception was diagnosed on translabial ultrasound and findings were analysed against symptoms and hiatal area in the levator ani muscle.

Rectal intussusception was found in 38 women (3.9%) and was more prevalent with increasing age (p = 0.014) and vaginal parity (p = 0.037). It was associated with symptoms of prolapse (p = 0.005), incomplete bowel emptying (p < 0.001), vaginal digitation (p < 0.001), and faecal incontinence (p = 0.022). RI was more common in patients with a clinical diagnosis of enterocele (p = 0.03) and rectocele (p = 0.002). On imaging, RI was associated with an increased hiatal area on valsalva (p < 0.001) and levator ani avulsion (p = 0.003).

Rectal intussusception is not an uncommon finding in urogynaecological patients. While often asymptomatic, it is associated with symptoms of vaginal prolapse, incomplete bowel emptying, vaginal digitation and faecal incontinence, and with abnormal levator ani structure and morphometry.