Background: Surgeons often approach anal fissure with chemical denervation (Botulinum toxin, BT)
instead of initial lateral internal sphincterotomy (LIS) due to concerns for long-term incontinence. We
evaluated the characteristics and outcomes of patients who received BT or LIS.
Methods: We performed a retrospective chart review of patients undergoing LIS and BT for anal fissure
between 2009 and 2015. In 2015, a telephone survey was performed to evaluate durability, long-term
incontinence and patient satisfaction.
Results: Ninety-four patients met criteria: 73 LIS and 21 BT. Age (BT 49 vs. LIS 52) was similar between
groups (p ¼ 1.0). Cleveland Clinic Fecal Incontinence (CCFI) score pre-intervention was higher in BT than
LIS patients (2.1 vs. 0.4, p ¼ 0.007) with fewer BT patients with perfect continence (50% vs. 88%). Telephone
survey response was 61%. Fissure recurrence was significantly higher for BT than LIS patients (36%
vs. 9%, p ¼ 0.03).
Conclusion: Patients undergoing LIS were less likely to recur. Both LIS and BT patients had some durable
changes in continence raising the question of whether there is a safe technique.
Summary for table of contents: Anal fissure is a painful condition that when not responding to medical
management, often is treated with Botulinum toxin injection or Lateral Internal Sphincterotomy. In this
retrospective review and telephone survey, we found that patients who underwent Botulinum toxin
injection had worse baseline incontinence than Lateral Internal Sphincterotomy patients and higher
recurrence rates. Both patient groups had durable changes in continence, which surgeons must consider
when treating patients with anal fissure.