Background/Objectives: To estimate long-term LARS prevalence after low anterior resection for rectal and selected rectosigmoid cancers and examine associated clinical factors and anorectal manometric findings. Methods: This single-center study retrospectively identified patients operated on during the period of 2014–2020 and assessed long-term function cross-sectionally in 2021. Of 120 eligible survivors with restored intestinal continuity, completed oncologic treatment, and no active recurrence/metastases, 103 participated. A study-specific, non-validated Turkish translation of the five-item LARS score and anorectal manometry were used; major LARS was defined as a score of 30–42. Results: Major LARS occurred in 36/103 patients (35.0%; 95% CI 26.4–44.5%) and any LARS in 53/103 (51.5%). Each 1 cm greater anastomotic height was associated with lower odds of major LARS (adjusted OR 0.67; 95% CI 0.52–0.86; p = 0.001), with a similar estimate when functional rather than surgical follow-up was included (adjusted OR 0.67; 95% CI 0.52–0.86). Manometric measures were inversely associated with LARS scores in exploratory adjusted cross-sectional models (Holm-adjusted p < 0.001 for all five measures). Conclusions: Within this selected long-term cohort, major LARS affected 35%. Lower anastomotic height was the most consistent clinical correlate; manometric differences were associations, not evidence of causation or postoperative physiological deterioration.