An anal fissure is a small tear in the lining of the anal canal, usually after passing a hard stool. Spasm of the anal sphincter keeps the tear from healing, so pain and bleeding can repeat with each bowel movement.
Key symptoms
- Sharp, tearing pain during and after bowel movements
- Small amounts of bright red blood on the toilet paper
- Pain that can last minutes to hours after passing stool
- Constipation and fear of having a bowel movement
What you find on exam
- Gentle look at the anus while spreading the buttocks
- Linear tear, most often in the back midline
- Skin tag next to the tear in long-standing cases
- Avoid a full rectal exam if pain is severe
Tests
- Usually a clinical diagnosis from history and inspection
- Colonoscopy if the tear is off the midline, multiple or the patient has warning signs
- Consider Crohn disease, infection or cancer for unusual fissures
Treatment basics
- More fiber and water, stool softeners such as docusate
- Warm sitz baths several times a day
- Topical nitroglycerin or diltiazem ointment to relax the sphincter
- Botulinum toxin injection or lateral internal sphincterotomy if it does not heal
Red flags
- Heavy bleeding or bleeding mixed into the stool
- Weight loss, change in bowel habits or anemia
- Fever with a painful lump suggesting an abscess
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.