Fistula Formation and Associated Factors among Adult Patients Underwent Surgery for Perianal Abscess at Asella Teaching and Referral Hospital, Southeast Ethiopia

Abstract

Abstract Background: Fistula-in-ano is a frequent complication after surgical drainage of perianal abscess, occurring in approximately one-third to half of patients. It develops due to ongoing infection and epithelialization of the abscess tract, leading to chronic morbidity and the need for repeated surgical procedures. Identifying factors associated with fistula formation is important for improving treatment outcomes and minimizing complications. Objectives: To assess rate of Fistula formation and associated factors Among adult Patients Underwent Surgery for Perianal Abscess at Asella Teaching and Referral Hospital, Southeast Ethiopia. Methods: A retrospective cross-sectional study was conducted for patients admitted and operated with diagnosis perianal abscess at General Surgery ward from February 2020 to February 2025. Data were extracted from medical records using a structured questionnaire, entered into Kobo-Toolbox, and analyzed with SPSS v27. Simple random sampling was used to select charts. Descriptive statistics and bivariable and multivariable logistic regression were used to identify factors associated with treatment outcomes, reported as AORs with 95% CI and p<0.05. Results: A total of 120 patients with perianal abscess were included in the study,of whom the majority were young adult males and rural residents. Subcutaneous abscess was the most common type, and the overall rate of fistula formation was 33.3%. On multivariable logistic regression, duration of illness greater than 48 hours (AOR = 3.36; 95% CI: 1.20–9.36; p = 0.021) and diabetes mellitus (AOR = 16.93; 95% CI: 1.41–203.43; p = 0.026) were independently associated with increased risk of fistula formation. Conclusion: Delayed presentation and diabetes mellitus are independent predictors of fistula formation among patients with perianal abscess. Early intervention and careful management of diabetic patients are essential to reduce the risk of this complication. Keywords: Perianal abscess, Fistula in ano, Diabetes mellitus, Duration of illness, Ethiopia