The aim of this study was to evaluate the impact of the transanal repair of rectocele and rectal mucosectomy with a single circular stapler (TRREMS) on the treatment of obstructed defecation due to rectocele and to identify the predictive factors for unsuccessful results. Consecutive patients with obstructed defecation symptoms (ODS) associated with rectocele who had the TRREMS procedure were included. Each patient was assessed by echodefecography, manometry, and colonic transit time as well as the Cleveland Clinic constipation score (CCS) before therapy and at follow-up after 6months. Reduction in the CCS score was calculated as a ratio. Factors correlated with a decrease in the CCS were analyzed in a univariate analysis. A total of 81 patients were included. Nineteen patients had postoperative complications that were not severe: 7 (8.6%) had tenesmus, 6 (7.4%) stenosis (4 treated with digital dilatation and 2 with endoscopic stricturectomy), 4 (4.9%) residual mucosal prolapse treated with rubber band ligation, 1 (1.2%) early bleeding, and 1(1.2%) thrombosis. Seventy-nine (97.5%) patients had a significant clinical response with significant reduction of the CCS constipation score from median 13 (range 17-10) to 4 (range, 8-2) (p = 0.0001); only 2 patients (2.5%) had an unsatisfactory response, complaining of straining and vaginal digitation during the evacuatory effort. Patients with anismus previously treated with biofeedback had a lower reduction ratio of the CCS score compared with patients without anismus (61.2 ± 2.8% versus 70.9% ± 1.5, p = 0.0006). There were no significant differences in the reduction of the CCS according to age, parity, type of delivery, previous hysterectomy, post-menopausal status, rectal mucosal prolapse and/or associated rectal intussusception, grade of rectocele and presence of complications. The TRREMS procedure significantly improved evacuation disorders in this study. Appropriate selection of patients is key for the success of this approach. Anismus even if previously treated with biofeedback, was the main predictive factor of unsuccessful treatment.