This chapter provides a summary of the aetiology, diagnosis, investigation and management of anal fissure. It gives an overview of clinical anatomy and pathophysiology related to anal fissure. Focusing on anal sphincter hypertonia as the key factor for anal fissure progression, the chapter draws attention to perpetuating factors that contribute to a vicious cycle of fissure non-healing and addresses management options for these factors. This chapter also looks at the way how different treatment options for anal fissure emerged over time and uses evidence-based medicine to compare these options.
An anal fissure is a superficial tear in the skin distal to the dentate line and is a cause of frequent emergency room visits. Anal fissures can be acute lasting less than 6 weeks or chronic more than 6 weeks. A small percentage of these may occur at the anterior midline.
Anal fissure is one of the most common anorectal problems. Anal fissure is largely associated with high anal sphincter pressures and most treatment options are based on reducing anal pressures. Conservative management, using increased fiber and warm baths, results in healing of approximately half of all anal fissures. In fissures that fail conservative care, various pharmacologic and surgical options offer satisfactory cure rates.