Prevalence and risk factors of low anterior resection syndrome: Meta-analysis with Subgroup Analysis.

BACKGROUND: The prevalence of major LARS and its associated risk factors remains variably reported in the literature. This meta-analysis aimed to assess the pooled prevalence of major LARS and to identify its predictive factors. METHODS: We conducted a meta-analysis in accordance with PRISMA 2020 and AMSTAR 2 guidelines to identify studies reporting the prevalence of major LARS or its associated risk factors. Subgroup analyses was used to explain heterogeneity. RESULTS: A total of 21 studies comprising 3,730 patients were included. The pooled prevalence of major LARS was 36.8% (95% CI: 30.1%-44.0%), with a 95% prediction interval of 12.0%-71.2%, indicating substantial heterogeneity. Tumor location < 5 cm from the anal margin (p < 0.001) and neoadjuvant radiochemotherapy (p = 0.006) were significantly associated with increased major LARS risk. No significant associations were found with anastomotic leakage, surgical approach, or stoma closure timing. CONCLUSION: Our meta-analysis showed a prevalence comparable to previously published data. Low tumor location and neoadjuvant radiochemotherapy were identified as two independent risk factors for major LARS. Prospective randomized trials are necessary to improve risk stratification for the development of major LARS.