Middle and Low Rectal Cancer

Brief Summaries Trial Purpose The primary objective of this prospective, randomized, multicenter, open-label, parallel-controlled clinical trial is to evaluate whether intraoperative rectal irrigation during laparoscopic radical resection of low-to-mid rectal cancer reduces postoperative local recurrence rates compared to no irrigation. Secondary objectives include assessing overall survival, incidence of postoperative complications (e.g., anastomotic leakage, stenosis), and quality of life at 6 months (EORTC QLQ-C30 scale). Participants Will: * Undergo laparoscopic radical resection with or without rectal irrigation (based on randomization); * Follow standardized Enhanced Recovery After Surgery (ERAS) protocols postoperatively; * Attend scheduled follow-ups at 3, 6, 12, 24, 36, and 60 months post-surgery, including clinical evaluations, imaging (CT/MRI), laboratory tests (CEA), and questionnaire assessments; * Maintain a symptom diary and record rescue inhaler usage (if applicable).