To investigate the application of NOSES under ERAS concept in laparoscopic radical resection of left colorectal cancer.

The clinical data of 80 patients with left colon cancer from January 2019 to December 2020 were retrospectively analyzed. The patients were divided into the conventional group and the Diluted group respectively，40 cases in each group. Both groups underwent laparoscopic radical resection of left colon cancer under the guidance of ERAS concept. In the conventional group，specimens were collected through auxiliary incision. SPSS 22.0 software was used to process the data. Independent t-test was used for perioperative indicators，repeated measurement an OVA was used for NRS pain score，and χ² test was performed for postoperative complications. P<0.05 indicated statistically significant differences.

There were no significant differences in operative time，intraoperative blood loss，number of lymph node dissection and drainage tube removal time between the two groups（P>0.05）. The first time out of bed，the time to exhaust，the time to defecate and the time to stay in hospital after the NOSES group were significantly reduced（P<0.05）. There is no interaction between time and method on THE NRS pain score（P>0.05）. The main effect of time and method on the NRS pain score is significant. The postoperative pain in the NOSES group is lighter than that in the conventional group（P<0.05）. The incidence of postoperative complications in the NOSES group was significantly lower than that in the conventional group（5.0% vs. 20.0%），and the difference was statistically significant（P<0.05）.

The combination of ERAS and NOSES in laparoscopic treatment of left colorectal cancer has the advantages of less pain，fewer complications and faster recovery，which is worthy of clinical application.