Comparative Evaluation of Lateral Internal Anal Sphincterotomy and Botulinum Toxin Injection in the Management of Chronic Fissure in Ano

Abstract Background: Chronic fissure-in-ano is a common anorectal condition characterized by severe pain and impaired quality of life, primarily due to sustained internal anal sphincter hypertonia and reduced anodermal blood flow. Aim: This study aimed to compare the clinical outcomes of lateral internal anal sphincterotomy and botulinum toxin injection in the management of chronic fissure-in-ano. Materials and Methods: This study was conducted in a tertiary care hospital and included 210 patients with chronic fissure in ano. Patients were randomized into two groups: Group A (lateral internal anal sphincterotomy, n = 105) and Group B (botulinum toxin injection, n = 105). Baseline demographic and clinical parameters were comparable between the groups. Statistical analysis was performed using appropriate comparative tests, with P < 0.05 considered statistically significant. Results: Intraoperative blood loss and immediate postoperative pain were significantly higher in the lateral internal anal sphincterotomy group ( P < 0.0001). However, pain scores at 1 month and 6 months were significantly lower in the sphincterotomy group ( P = 0.01 and P = 0.001, respectively). Conclusion: Lateral internal anal sphincterotomy provides superior medium- and long-term outcomes in terms of pain relief, healing, effectiveness, and recurrence compared to botulinum toxin injection, with an acceptable and largely transient impact on continence.