Review Question - QID 104563

This patient who eats a low-fiber diet presenting with pain during defecation and a fissure on rectal exam most likely has an acute anal fissure. Initial therapy for this patient would include stool softeners and topical analgesics.

An anal fissure is one of the most common benign anorectal conditions that may result from high anal pressure. Anal fissures can occur because of the anal mucosa stretching beyond its normal capacity. Once the tear occurs, the exposed internal sphincter muscle spasms, further tearing the mucosa. Initially, they can be managed with stool softeners, local pain control, high-fiber diet, and sitz baths. Medical management with nitroglycerin ointment or onabotulinumtoxin A injections are helpful as next steps if the aforementioned measures are insufficient. Once it becomes a chronic problem, surgical treatment such as lateral internal sphincterotomy may be necessary.

Beaty et al. review the symptoms, pathophysiology, and management of anal fissures. They found that the majority of acute anal fissures resolve with non-operative treatments. They recommend that careful work-up and maximizing of medical therapy be employed in patients with Crohn disease or HIV.

Figure A shows a superficial, shallow laceration in the posterior anal midline.

Incorrect Answers:
Answer 1: Colonoscopy would be useful to further examine the cause of his pain and blood, but it is clear from the history and physical exam that this is a fissure. It is plausible to set up a colonoscopy in addition to treating the fissure present.

Answers 2: Nitroglycerin ointment acts as a vasodilator and encourages increased blood flow to the area of the fissure, thus increasing the rate of healing. Common side effects include headache and hypotension. This tends to be the next step in management if the fissure persists despite stool softeners, high-fiber diet, and sitz baths.

Answer 3: Onabotulinumtoxin A injections serve to relax sphincter tone, promoting blood flow to the area of the fissure to promote healing. This method is typically reserved for chronic anal fissures after more conservative measures such as stool softeners, fiber, or topical calcium channel blockers or nitroglycerin have failed.

Answer 4: Surgical repair is reserved for refractory cases. The internal sphincter is divided in the lateral position (lateral internal sphincterotomy). One complication of the surgery is fecal incontinence, which is typically transient and resolves.

Bullet Summary:
Anal fissures are initially treated with stool softeners and topical analgesics.