Objective To explore the effects of long-term regular aspirin use on the recurrence and bleeding in elderly postoperative patients with colorectal adenocarcinoma after surgery,and to analyze the risk factors affecting pa-tient recurrence.Methods Two hundred and fifty-two elderly patients with colorectal adenocarcinoma who underwent surgical treatment at Ninth People's Hospital Affiliated with Shanghai Jiaotong University School of Medicine from Janu-ary 2013 to October 2019 were retrospectively analyzed.Divide patients into an aspirin group(n=49)and a non aspirin group(n=203)based on whether they have been taking aspirin(100 mg/d)continuously for ≥ 6 months after surgi-cal treatment.Compare general information such as age,gender,smoking history,and alcohol consumption history be-tween two groups of patients,as well as preoperative blood test results,pathological diagnosis,surgical data,and follow-up and follow-up within 2 years after surgery.Analyze the impact of regularly taking aspirin for ≥6 months on the recur-rence and gastrointestinal bleeding of patients within 2 years.Results(1)The postoperative recurrence rate of the as-pirin group was lower than that of the non aspirin group(P<0.05),and there was no statistically significant difference in gastrointestinal bleeding.(2)Among the subgroups with preoperative intestinal obstruction,the aspirin group had a higher incidence of gastrointestinal bleeding complications compared to the non aspirin group,and the difference was sta-tistically significant(P<0.05).(3)Older age,TNM stage Ⅳ,≥ 3 comorbidities at diagnosis,palliative surgery,and no chemotherapy after surgery were associated with an increased risk of postoperative recurrence in elderly patients with colorectal adenocarcinoma.Regular use of aspirin(100 mg/d)for≥ 6 months was associated with a reduced risk of re-currence.Conclusions Postoperative patients with elderly colorectal adenocarcinoma can reduce recurrence by regular-ly taking aspirin for a long time.At the same time,complications such as gastrointestinal bleeding may occur.