Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 15-44: Other Anal Conditions: Fissures, Abscess, Pruritus + Key Features Download Section PDF Listen +++ ++ 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 Download Section PDF Listen +++ ++ 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 Download Section PDF Listen +++ ++ 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 Download Section PDF Listen +++ ++ 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 0.2–0.4% 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