Definition An anal fissure is a small tear or cut in the lining of the anal canal. Etiology Constipation: Hard stools causing trauma. Chronic diarrhoea. Anal intercourse. Childbirth trauma. Inflammatory bowel diseases (less common). Clinical Presentation Severe, sharp pain during and after bowel movements. Bright red blood on the toilet paper or in the stool. Pruritus (itching). A visible tear or cut near the anus (on inspection). Classification Acute: Less than 6 weeks’ duration. Chronic: More than 6 weeks’ duration, may have an external skin tag (sentinel pile) at the distal end. Investigations Generally clinical diagnosis. Anoscopy or proctoscopy: If other diagnoses are being considered or if the fissure doesn’t heal with treatment. Management Conservative: Bulk-forming laxatives to soften stools (e.g., ispaghula husk). Sitz baths: Warm water baths for symptomatic relief. Topical anaesthetics (e.g., lidocaine) for pain relief. Medical: Topical glyceryl trinitrate (GTN): Reduces anal sphincter spasm. Topical calcium channel blockers (e.g., diltiazem). Botulinum toxin injections: Temporary paralysis of the anal sphincter. Surgical: Reserved for chronic fissures not responding to treatment. Lateral internal sphincterotomy: Most common surgical treatment. Fissurectomy: Removal of the fissure and any underlying scar tissue. Complications Chronic pain. Abscess or fistula formation. Incontinence (rare and usually temporary, especially after surgery). Prevention High-fibre diet to prevent constipation. Regular fluid intake. Avoiding straining during bowel movements.