Efficacy and Safety of Stapled Transanal Rectal Resection (STARR) for Obstructed Defecation Syndrome: A Systematic Review and Meta-Analysis of Comparative Studies

Background/Objectives: Stapled transanal rectal resection (STARR), introduced in 2004 for obstructed defecation syndrome (ODS), remains of uncertain comparative efficacy and safety relative to other therapeutic approaches. This study systematically evaluated and meta-analyzed STARR surgery versus alternative interventions for ODS. Methods: MEDLINE (PubMed), CENTRAL, ProQuest, SAGE, and Web of Science were searched up to May 2026 for randomized controlled trials and observational comparative studies evaluating STARR against any comparator for ODS. Primary outcomes included improvement in validated ODS constipation scores and postoperative morbidity (bleeding, pain, urgency/incontinence). Secondary outcomes were operation time and hospital length of stay. Pooled effect sizes were calculated using random-effects models, heterogeneity assessed via I2 statistics, and cumulative meta-analyses performed to examine temporal trends. Results: Twelve studies (4 RCTs, 8 observational) comprising 995 participants were included. No significant difference in ODS score improvement was found between STARR and comparators (SMD = 0.26, 95% CI: −0.17 to 0.70; I2 = 89.2%); however, due to substantial clinical and statistical heterogeneity and wide prediction intervals, this pooled estimate reflects an average of diverse underlying effects rather than a single definitive treatment effect with cumulative analysis revealing loss of initial efficacy after 2010. STARR showed numerically higher but non-significant odds of bleeding (OR = 1.73) and urgency/incontinence (OR = 2.91), with comparable postoperative pain (OR = 0.70). STARR demonstrated significantly shorter operation time (MD = −21.23 min) and hospital stay (MD = −1.15 days). Conclusions: STARR surgery offers no superior efficacy in ODS symptom improvement compared with alternative treatments. However, the extreme heterogeneity of the primary outcome limits the interpretive value of the pooled estimates. While there are numerically higher odds of postoperative bleeding and urgency/incontinence, these differences did not reach statistical significance. STARR is associated with significantly shorter operation time and hospital stay. The declining effect size over time and substantial heterogeneity suggest that patient selection is critical. Future large multicenter RCTs with long-term follow-up and standardized patient-reported outcomes are needed to define optimal surgical strategies for specific ODS phenotypes.