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An anal fissure is a common benign anorectal condition affecting both children and adults. It is a painful linear tear in the posterior anoderm extending superiorly to the dentate line. Classically, anal fissures are caused by forceful expulsion of large, firm bowel contents. This activity reviews the pathophysiology and management strategies for anal fissures, as well as the indications for and techniques involved in performing an internal anal sphincterotomy. This activity highlights the interprofessional team's role in managing affected patients. Objectives: Identify the anatomy of the anal canal. Determine the indications for an anal sphincterotomy. Assess the complications associated with anal sphincterotomies. Communicate interprofessional team strategies for improving care coordination and communication to advance the safe performance of anal sphincterotomies and optimize patient outcomes. Access free multiple choice questions on this topic.

An anal fissure is a common benign anorectal disease affecting both children and adults. It is a painful linear tear in the posterior anoderm extending the cephalad to the dentate line. Classically, these are caused by a large, firm, forceful bowel movement. This results in cycles of recurring anal pain and bleeding, leading to chronic anal fissures in as many as 40% of patients who develops fissures. An anal fissure can typically be diagnosed based on history alone. Patients describe moderate to severe anal pain with bowel movements with variable amounts of bleeding. The bleeding is described as blood on the toilet paper with wiping. The pain commonly persists for 15 to 30 minutes following a bowel movement. The exposed internal anal sphincter frequently spasms, leading to significant pain. If this persists, this muscle becomes hypertrophied leading to nonhealing anal fissures. Typically, these are self-limiting in children, whereas in adults, these can require surgical intervention.[1][2][3][4] The majority of anal fissures (90%) are located in the posterior midline. Fissures can be located in the anterior midline in as many as 25% of females and 8% of males. Fissures in the lateral position should raise concerns about other disease processes like inflammatory bowel disease or granulomatous diseases. Several medical therapies, including salves, fiber, and topical nitroglycerin, aid in spontaneous closure early in the disease process. Surgical therapies include botulinum toxin injections, fissurectomy, advancement flaps, and internal lateral anal sphincterotomy. Surgical intervention is typically indicated with chronic fissures or for fissures that are not amenable to medical therapy. Internal lateral anal sphincterotomy was first introduced in 1951 by Eisenhammer. The procedure provides prompt symptomatic relief by reducing pathologically elevated pressures within the anal canal. The procedure has provided a greater than 95% cure rate at 3 weeks post-procedure.  Currently, it is considered the gold standard surgical intervention.

The major complication associated with internal anal sphincterotomy is anal incontinence. Up to 50% of patients experience transient incontinence, varying from the inability to control gas to loss of formed stool, resulting in soiling. However, anal incontinence resolves in the majority of patients.  In a meta-analysis of 22 retrospective and prospective studies, 4512 patients were followed for more than 2 years after a lateral internal sphincterotomy for the chronic anal fissure. In this study, the overall continence disturbance rate was 14%. The rate for major incontinence, defined as involuntary loss of feces, was less than 2%. Some experts have advocated limiting the sphincterotomy to the length of the fissure, which has been shown to reduce the risk of incontinence. However, this is associated with an increased risk for non-healing fissures or recurrence of fissures. Other minor complications of internal anal sphincterotomy include infection, bleeding, and fistula development.[8]

Anal fissures often lead to a poor quality of life because of inappropriate or inadequate treatment. The primary caregiver should always refer these patients to a colorectal surgeon because of the enormous morbidity. The condition is best managed by an interprofessional team that includes a colorectal surgeon, dietitian, general surgeon, and a gastroenterologist. A proper anal internal sphincterotomy is required in adults to prevent fecal incontinence.