OBJECTIVE: To compare surgeons' intraoperative surgeon acceptability or assessment of the operative field regarding bowel contents and patients' satisfaction with or without a mechanical bowel preparation before reconstructive vaginal prolapse surgery. METHODS: In this single-blind, randomized trial, women scheduled to undergo vaginal prolapse surgery with a planned apical suspension and posterior colporrhaphy were allocated using block randomization to an intervention or control group. Surgeons were blinded to patient allocation. One day before surgery, mechanical bowel preparation instructions consisted of a clear liquid diet and two self-administered saline enemas; the participants in the control group sustained a regular diet and nothing by mouth after midnight. The primary outcome was surgeons' intraoperative assessment of the surgical field regarding bowel content as measured on a 4-point Likert scale (1, excellent; 4, poor). Secondary outcomes included participant satisfaction and bowel symptoms. The primary outcome was determined by intention-to-treat analysis and other analyses were per protocol. RESULTS: Of the 150 women randomized (75 women to intervention and control group), 145 completed the study. No differences existed in the demographic, clinical, and intraoperative characteristics between groups (P>.05). Surgeons' intraoperative assessment rating was 85% "excellent or good" with bowel preparation compared with 90% for participants in the control group (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.21-1.61; P=.30). The bowel preparation group was less likely to report "complete" satisfaction compared with the participants in the control group (OR 0.11, 95% CI 0.04-0.35; P<.001). Abdominal fullness and cramping, fatigue, anal irritation, and hunger pains were greater in the bowel preparation group (all P<.01). CONCLUSION: Before reconstructive vaginal surgery, mechanical bowel preparation conferred no benefit regarding surgeons' intraoperative assessment of the operative field, reflected decreased patient satisfaction, and had increased abdominal symptoms. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT01431040. LEVEL OF EVIDENCE: I.