Comparison of Treatment Success of Botox Injection in the Internal Sphincter Versus Isosorbidedinitrate Ointment in Patients With an Anal Fissure

Botulin Toxin Versus Isosorbidedinitrate Ointment in Treatment Anal Fissure; A Prospective, Blinded, Randomized Trial

The standard treatment of anal fissure in the netherlands (ISDN ointment) is being compared to a relatively new treatment (injection of Botox in the internal anal sphincter). The study hypothesis is that after 4 months, Botox has healed more patients than ISDN. The comparison is done blinded for the surgeon and the patient.

Inclusion Criteria:

• all consecutive patients over the age of 18 with a chronic anal fissure presenting to our surgical outpatient clinic

Exclusion Criteria:

• pregnancy
• previous anal surgery
• Crohn's disease
• systemic causes of an anal fissure