Purpose: Anal fistula is a common condition in proctology, usually requiring surgical treatment. Few risk factors have been clearly identified based on solid evidence. Our research objective was to determine whether history of anal surgery was a risk factor for subsequent anal fistula. Methods: We conducted a case-control study from January 1, 2012 through December 31, 2013 in our tertiary center, comprising 280 cases that underwent surgery for anal fistula and 123 control patients seeking a consultation for upper gastrointestinal symptoms. Patients with inflammatory bowel disease were excluded. For both cases and controls, the following variables were recorded: sex, any prior anal surgery, diabetes mellitus, infection with human immunodeficiency virus, and smoking status. For each variable, confidence interval and odds ratio (OR) were calculated. Results: In univariate analysis, male sex (73.2% vs. 31.7%, P < 0.0001), active smoking (38.1% vs. 22%, P = 0.0015), and prior anal surgery (16.0% vs. 4.1%, P = 0.0008) were associated with higher risk of anal fistula. In multivariate analysis, only male sex (OR, 5.5; 95% confidence interval [CI], 5.42 to 9.10; P < 0.0001) and previous anal surgery (OR, 4.48; 95% CI, 1.79 to 13.7; P = 0.0008) remained independently associated with anal fistula occurrence. Conclusion The epidemiology of anal fistula is poorly assessed despite the high frequency at which it is diagnosed. Our findings suggest that history of any kind of anal surgery is a risk factor for further onset of anal fistula. Surgeons and patients must be informed of this issue.

Purpose: The aim of this study was to assess frequency and risk factors of severe bleeding after proctological surgery requiring hemostatic surgery observed after publication of the French guidelines for anticoagulant and platelet-inhibitor treatment. Methods: All patients who underwent proctological surgery between January 2012 and March 2017 in a referral center were included. Delay, severity of bleeding, and need for blood transfusion were recorded. Patients with severe postoperative bleeding were matched to controls at a 2:1 ratio adjusted on the operator, and the type of surgery. Results: Among the 8,890 operated patients, 65 (0.7%) needed a postoperative hemostatic procedure in an operating room. The risk of a hemostatic surgery was significantly increased after hemorrhoidal surgery compared with other procedures (1.9% vs. 0.5%, P<10–4) and was most frequent after Milligan-Morgan hemorrhoidectomy (2.5%). Mean bleeding time was 6.2 days and no bleeding occurred after day 15. Blood transfusion rate was 0.1%. Treatment with anticoagulants and platelet inhibitors were managed according to recommendations and did not increase the severity of bleeding. The risk of severe bleeding was significantly lower in active smokers vs. non-smokers in univariate (16.9% vs. 36.2%, P=0.007) and multivariate (odds ratio, 0.31; 95% confidence interval, 0.14–0.65) analysis whereas sex, age, and body mass were not significantly associated with bleeding. Conclusion Severe postoperative bleeding occurs in 0.7% of patients, but varies with type of procedure and is not affected by anticoagulant or antiplatelet treatment. These treatments given in accordance with the new guidelines do not increase the severity of postoperative bleeding.