Overview
An anal fissure is a small, oval-shaped tear in the thin, moist tissue (mucosa) that lines the anus. It can cause intense pain during and after bowel movements, often accompanied by bright red blood on the stool or toilet paper. Anal fissures are a common cause of rectal bleeding and anal pain, affecting people of all ages, though they are most common in infants and middle-aged adults.
Most acute anal fissures heal on their own within a few weeks with conservative measures like increased fiber intake and sitz baths. However, some may become chronic and require medical or surgical intervention.
Symptoms
Common symptoms of an anal fissure include:
• Sharp, severe pain during bowel movements that may last for minutes to hours afterward.
• Bright red blood on the stool, toilet paper, or in the toilet bowl.
• Itching or irritation around the anus.
• A visible tear or crack in the skin around the anus.
• A small skin tag or lump near the fissure.
• Muscle spasms in the anal sphincter.
• Burning or stinging sensation in the anal area.
Causes
Anal fissures are most commonly caused by trauma to the anal lining, often from:
• Passing hard or large stools due to constipation.
• Chronic diarrhea.
• Childbirth (tearing during delivery).
• Anal intercourse.
• Inserting foreign objects into the anus.
• Reduced blood flow to the anus.
• Tight anal sphincter muscles (hypertonic sphincter).
• Inflammatory bowel diseases like Crohn's disease.
• Certain infections or cancers.
Treatment
Treatment options depend on whether the fissure is acute or chronic:
Conservative measures:
• High-fiber diet and increased water intake to soften stools.
• Stool softeners or laxatives.
• Sitz baths (soaking in warm water for 10–20 minutes several times a day).
• Topical anesthetics (e.g., lidocaine) for pain relief.
• Hydrocortisone creams to reduce inflammation.
Medical therapies:
• Prescription ointments like nitroglycerin or calcium channel blockers (diltiazem, nifedipine) to relax the sphincter and improve blood flow.
• Botox injections to temporarily paralyze the anal sphincter.
Surgical options:
• Lateral internal sphincterotomy (LIS) – the most effective treatment for chronic fissures.
• Anal advancement flap – for fissures that don't heal with other treatments.