Background: Anal fissures, longitudinal tears in the anal canal, can become chronic if unhealed after 8–12 weeks. Treatment
options for chronic fissures include Botulinum toxin (Botox) injections and tailored lateral internal sphincterotomy (LIS).
Objective: This study aimed to compare the effectiveness and safety of unilateral Botox injection versus tailored LIS for
treating chronic anal fissures.
Patients and Methods: A single-blinded, randomized, controlled trial was conducted on patients with chronic anal fissure
at Mansoura University Hospital from September 2021 to February 2023. Patients were randomly assigned to receive
either unilateral Botox injection (group A, n=35) or tailored LIS (group B, n=35). Pre- and postoperative assessments
included clinical examination, manometry, and evaluation of incontinence and recurrence rates.
Results: The mean operative time was significantly longer in group B (11.46±1.82 min) compared with group A (6.11±1.59
min, P<0.001). Wound healing was faster in group A (5.43±1.70 days) versus group B (10.83±2.20 days, P<0.001).
Recurrence rates were lower in group B (22.9%) compared with group A (42.9%, P=0.075). Incontinence to flatus was
lower in group B (22.9%) than in group A (40%, P=0.122). Incontinence to solid stool was absent in group B but present
in 11.4% of group A (P=0.039).
Conclusion: Tailored lateral internal sphincterotomy showed superior long-term outcomes in recurrence and incontinence
compared with unilateral Botox injection. Despite a longer healing period, tailored LIS should be preferred for managing
chronic anal fissures.