Anal Fissures

Key Features

• Linear or rocket-shaped ulcers, usually < 5 mm

• Most commonly occur in the posterior midline; 10% occur anteriorly

• Arise from trauma during defecation

Clinical Findings

• Severe, tearing pain during defecation followed by throbbing discomfort

• May lead to constipation because of fear of recurrent pain

• Mild associated hematochezia

• With chronic fissures, there is fibrosis and a skin tag at the outermost edge (sentinel pile)

Diagnosis

• Diagnosis is confirmed by visual inspection of the anal verge while gently separating the buttocks

• Digital and anoscopic examinations may cause severe pain and may not be possible

• Fissures that occur off the midline suggest

  • Crohn disease

  • Syphilis

  • Tuberculosis

  • HIV/AIDS

  • Anal carcinoma

Treatment

• Fiber supplements, stool softeners

• Sitz baths

• Topical anesthetics (5% lidocaine; 2.5% lidocaine plus 2.5% prilocaine) may provide temporary relief

• Chronic fissures may be treated with

  • Topical 0.125–0.4% nitroglycerin or diltiazem 2% or nifedipine 0.5% ointment (1 cm of ointment) applied just inside anus with tip of finger twice daily for 4–8 weeks

  • Injection of botulinum toxin (20 units) into internal anal sphincter

  • These treatments result in healing in 50–80% of patients with chronic anal fissure, but headaches occur in up to 40% of patients treated with nitroglycerin

• Botulinum toxin may cause transient anal incontinence

• Internal sphincterotomy is effective for chronic or recurrent fissures but may be complicated by minor fecal incontinence