The purpose of this study is to evaluate the appropriate timing to do preventive ileostomy closure after total mesorectal excision of rectal cancer. To evaluate the effectiveness and safety of preventive ileostomy closure at different time (12 weeks / 24 weeks after radical resection of rectal carcinoma). This study was expected to demonstrate that the early preventive ileostomy closure after total mesorectal excision of rectal cancer does not increase the risk of complications.

A temporary stoma may, in fact, result in reduced quality of life because of feelings of physical and mental restriction, debilitating nuisance, among other problems. Skin irritation, prolapse, and retractionare quite common after ileostomy. A high incidence of parastomal hernia, ileus, and increased salt and fluid loss has been reported, which may also contribute to greater willingness of both the surgeon and patient to close the temporary stoma as soon as possible.

Currently, it remains unclear whether stoma closure should be performed after the end of chemotherapy or during chemotherapy (12 weeks or 24 weeks after radical resection of rectal carcinoma).

The aim of this study is to assess the possible impact of stoma closure timing on postoperative results and to evaluate that the early preventive ileostomy closure after total mesorectal excision of rectal cancer does not increase the risk of complications.

Inclusion Criteria:

• sign the informed consent
• postoperative pathology is rectal adenocarcinoma
• primary middle and low rectal cancer patients (tumor distance from the anal margin is less than 10 cm)
• underwent total mesorectal excision for rectal cancer with preventive loop ileostomy

Exclusion Criteria:

• postoperative pathology is not rectal adenocarcinoma (rectal neuroendocrine tumor, lymphoma, etc.)
• postoperative pathologic staging of rectal cancer is I phase, II phase
• underwent total mesorectal excision for rectal cancer without preventive loop ileostomy
• emergency operation for rectal cancer
• disease progression (local recurrence or distant metastasis, etc.)
• anastomotic stenosis
• serious system disease, including heart dysfunction, respiratory insufficiency, liver and kidney dysfunction, serious blood diseases
• participate in other clinical trial
• pregnancy or perinatal woman
• combined with other malignant tumor
• with a history of neurological and psychiatric disorders
• patients with abnormal bone marrow suppression after chemotherapy

Individual participant data for all primary and secondary outcome measures will be made available within 6 months of study completion.