Rectoceles occur frequently among parous women and they are thought to be due to disruption or distension of the rectovaginal septum as a result of childbirth. However, the etiology of rectocele is likely to be more complex since posterior compartment prolapse does occur in nulliparous women. This study was designed to determine the role of childbearing as an etiological factor in true radiological rectocele. A true rectocele was identified in 4% of women antenatally and in 16% after childbirth (P < 0.001). Mean rectocele depth was 13.5 mm (10 – 23.2 mm). The mean antepartum position of the rectal ampulla on Valsalva maneuver was 4.39 mm above and it was 1.64 mm below the symphysis pubis postpartum (P < 0.0001). De novo appearance of true rectocele showed significant association to a history of previous <20 weeks pregnancy and fetal birth weight. Body mass index and length of the second stage were related to rectocele depth increase.
Childbirth appears to play a distinct role in the pathogenesis of rectocele. Both maternal and fetal factors appear to contribute.