In recent years medicinal treatment has become established as the first line treatment for chronic anal fissures. Topically applied calcium antagonists and nitrates lead to a reduction in anal sphincter pressure, improvement in perfusion and a higher healing rate of 60-70% with good evidence compared to placebo. The healing rates of calcium channel blockers and nitrates do not significantly differ. Nitrates have a higher rate of side effects (especially headache) and a concentration of 0.2% glyceryl trinitrate (GTN) applied three times daily is sufficient. Calcium antagonists, on the other hand, are not approved for the treatment of anal fissure in Germany (off-label use). There is a NRF-recipe (neues Rezeptur-Formularium, NRF) for a 2% diltiazem cream applied twice daily. The treatment is carried out for 6-8 weeks until the absolutely necessary control examination, maybe longer in cases of partial remission. In addition, regulation of bowel movements (mostly with Psyllium seed husks) and correct defecation behavior are important and should be maintained to prevent relapse. In cases of treatment failure another treatment (e.g. fissurectomy according to Gabriel, alternatively botulinum toxin) is recommended. In cases of a (subanodermal) fistula or pronounced secondary alterations, primary surgery without prior medicinal treatment is justified.
