This study is aimed at identifying risk factors of Low Anterior Resection Syndrome following ileostomy reversal in rectal cancer patients who had undergone preventive ileostomy. This retrospective analysis was conducted on a cohort of 605 patients treated at the Fourth Hospital of Hebei Medical University between January 2018 and December 2021. These patients were grouped based on LARS score, and Clinical and follow-up data were collected to conduct univariate analyses of potential factors influencing LARS occurrence based on variable type. Variables with statistical significance were included in a logistic regression model to analyze potential influences on the occurrence of LARS. Univariate and Multivariate logistic regression analysis showed that N2 stage (OR = 2.290 95%CI: 1.076-4.873, P = 0.031), chemoradiotherapy (OR = 2.271, 95%CI: 1.246-4.138, P = 0.007), and anastomosis height (OR = 0.836, 95%CI: 0.717-0.975, P = 0.022) were independent influences on the occurrence of LARS. In model 3 (adjusting for all covariates), the relationship between anastomotic height and patient LARS status showed a negative correlation. In subgroup analyses, there were significant differences in the effect of anastomotic height on LARS in subgroups with different hemoglobin concentrations. A high occurrence rate of LARS is observed in rectal cancer patients with preventive ileostomy reversal. N2 stage, history of chemoradiotherapy, and anastomotic height are independent influence factors for the occurrence of major LARS after ileostomy reversal.© 2024. The Author(s).