Long-term outcome of the use of botulinum toxin injection for functional anal pain
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Published on: June 23, 2023
J R F Hollingshead1, Y Maeda, T J Brown
1St Mark's Hospital, Harrow, Middlesex, UK.
Aim:
Anal pain may occur in the absence of demonstrable anal pathology. Spasm of the sphincter muscles has been suggested as a cause in some patients. We aimed to assess the effectiveness of injection of botulinum toxin in treating this condition.
Method:
Patients who had injection of botulinum toxin over a 3-year period were identified retrospectively. Patients were excluded if anal fissure or other organic pathology was found to account for their symptoms on examination under anaesthetic. Long-term outcome was assessed at a minimum 3-year post-procedure telephone follow up.
Results:
Fourteen (eight male) patients were identified, of median age 50 years. Botulinum toxin (20-200 u) was injected into the internal sphincter. Seven of the 14 patients reported significant improvement in symptoms at 3 months. Seven were available for a structured telephone review at a median of 59 (42-68) months. The four patients who had benefited from the injection had remained asymptomatic.
Conclusion:
Injection of botulinum toxin into the internal anal sphincter has a role in alleviating symptoms in a small proportion of patients with functional anal pain.
