The key target for treatment is relief of pain and facilitation of healing through reduction of anal sphincter pressure.2
The surgical procedure, lateral sphincterotomy, involves division of the internal anal sphincter (IAS). This improves symptoms and promotes healing, but risks causing faecal incontinence (in up to 45% of cases).3
Pharmacological treatments have the advantage of avoiding damage to the IAS. Glyceryl trinitrate (GTN) ointment [Rectogesic / Rectiv], applied locally, relaxes the IAS. It has licensing authorisation for the relief of pain associated with chronic anal fissure. However, it causes headache in up to 57% of patients,4 which can result in poor compliance and treatment failure.