Objective:The aim of this study was to evaluate the safety and efficacy of three-cavity clearance(TCC)used for the treatment of perianal abscess.Methods:A case–control study of patients with perianal abscess was conducted at the Second and Third Affiliated Hospitals of Nanjing University of Chinese Medicine from June 2013 to March 2016.Clinical data from 46 patients who had TCC were analysed.At the same time,46 patients had simple incision and drainage and 46 patients had abscess drainage and cutting seton(radical abscess incision);the data from these patients were also analysed.The length of hospital stay,time of wound healing,fistula rate and anal incontinence were assessed.Results:The rate of fistula formation in the TCC group was 13.0%—significantly lower than that in the group with simple incision and drainage(39.1%,p<0.01)and similar to the group with radical abscess incision(8.7%,p>0.05).Two patients(4.3%)in the group with radical abscess incision had anal incontinence,flatus and soiling;their Wexner scores were 6 and 3,respectively.There was no anal incontinence in the TCC group or the simple incision and drainage group.There were no statistical differences in the time of wound healing and length of hospital stay among the three groups(both p>0.05).Conclusion:TCC is a safe and effective sphincter-preserving procedure for perianal abscess formation and can decrease the fistula rate after perianal abscess drainage.It appears to be a valuable method that can be used in clinical practice;however,further studies are needed to verify this finding.