ObjectiveTo investigate the influence of surgical treatment on early postoperative anal function in left colon cancer patients with acute complete obstruction. MethodsThe clinical data of left colon cancer patients with acute complete obstruction were retrospectively chosen from January 2017 to June 2020 in Yibin Second People’s Hospital. The patients were grouped according to the treatment plan including emergency operation group (54 cases), stent+operation group (46 cases) and stent+neoadjuvant chemotherapy (NAC)+operation group (44 cases). The anal function was evaluated at 4 weeks, 1 month and 6 months after operation, and quality of life was evaluated at 12 months after operation. Unconditional logistic regression model was used to explore the factors influencing early postoperative anal function injury. Results The proportion of open surgery in the emergency operation group was statistically higher than the stent+operation group and stent+NAC+operation group (P<0.05). The low anterior rectum resection syndrome (LARS) score at 4 weeks after operation of the emergency operation group was statistically higher than those of the stent+operation group and stent+NAC+operation group (P<0.05). However there was no statistical difference in LARS score at 1 month and 6 months after operation among the three groups (P>0.05). The score of social function in the emergency operation group at 12 months after operation was statistically lower than those of the stent+operation group and stent+NAC+operation group (P<0.05). Multivariate logistic regression analysis showed that body mass index (BMI) ≥24 kg/m2, emergency operation, and Eastern Collaborative Oncology Group (ECOG) score were the risk factors for early postoperative anal dysfunction in the left colon cancer patients with acute complete obstruction (P<0.05). ConclusionsLeft colon cancer patients complicated with acute complete obstruction who only received emergency surgery, BMI≥24 kg/m2, or one score of ECOG are more likely to have functional impairment, and the quality of life of those patients underwent emergency surgery alone is decreased. In addition, the stent placement at the obstruction site should be helpful to avoid the above problems.