Stool outlet obstruction (SOO) in rectoceles is a complex urogynaecological entity with thorough therapeutic challenges. Surgery to correct rectocele is a common treatment option targeted toward restoration of anatomy and relief of symptoms like bulge and obstructed defecation. The aim of this prospective study is to determine the efficacy of preoperative digitations/pessary use in patients with rectocele and SOO.

Patients who suffered from rectocele with SOO were included in this comparative mono-center study from 2015 to 2022. The primary outcome of this study was persistent postoperative obstruction. The preoperative rectocele stage was determined according to the Pelvic Organ Prolapse Quantification System (POP-Q), and a pessary test was performed with pessaries or digital support of the posterior vaginal wall for defecation (digitation). All patients underwent a preoperative magnetic resonance imaging (MRI) defaecography to detect intussusception. If intussusception was detected, a laparoscopic rectopexy was performed; otherwise, a native-tissue posterior colporrhaphy with correction of the Denonvillian fascia. Follow-up took place after six weeks and included patient-reported symptoms and clinical examination.

50 patients were included, aged between 34 and 91 years, with a median of 63.5 years and a median body mass index of 28 kg/m2 (range 18.5-34 kg/m2). Most patients had a rectocele grade III (n=31, 62%), and the remaining had a rectocele grade II (n=19, 38%). Intussusception was diagnosed by MRI defaecography in 11 patients (22%). The pessary test was positive in 38 patients (OR 38, p<0.001, 5.22 - 276.77) and negative in all patients with intussusception. Consequently, 11 patients underwent rectopexy (22%) and 39 posterior colporrhaphy (78%).
After posterior colporrhaphy, only one patient had persisting SOO (OR 0.26, p<.001, 95%CI .003 – .192) as well as one after rectopexy (OR 3.8, p=.36, 95%CI 22 – 66.2): The patient with persistent SOO after posterior colporrhaphy was the one with a negative pessary-test. The patient with postoperative SOO after rectopexy had a persistent, very low rectocele. Further postoperative complication was a de novo anal incontinence (Parks II) after posterior repair (n=1).

All patients who underwent posterior repair with a previously positive pessary test presented a complete recovery of SOO postoperatively. Whether the pessary test can replace the unpleasant defaecography in the future needs to be researched further, including extensive follow-up studies.

The pessary test appears to be a simple and effective measure to (i) predict the success rate in patients undergoing native-tissue posterior colporrhaphy, (ii) differentiate between intussusception in patients with rectocele and SOO and consequently (iii) indicate the correct surgical treatment.