Virtual Ileostomy Versus Conventional Loop Ileostomy

Inclusion Criteria: * Pathologically confirmed low to intermediate level rectal cancer, with the lower margin of anastomosis \<10cm from the anus. * age ≥18 years and ≤80 years. * the surgical procedure is anterior rectal resection (LAR). * intraoperative virtual or conventional ileostomy was performed. Exclusion Criteria: * BMI \>30 kg/m². * ASA score \>3. * Patients with coexisting complete intestinal obstruction. * History of long-term use of immunosuppressive drugs or glucocorticoids. * Combined severe cardiac disease: with congestive heart failure or NYHA cardiac function ≥ grade 2. Patients with a history of myocardial infarction or coronary artery surgery within 6 months prior to the procedure. * chronic renal failure (requiring dialysis or glomerular filtration rate \<30 mL/min). Intraoperative combined multi-organ resection. * Combined cirrhosis of the liver. * Intraoperative findings of incomplete anastomosis and positive insufflation test.