An anal fissure is a small tear in the thin, moist tissue (mucosa) that lines the anus. An anal fissure may occur when you pass hard or large stools during a bowel movement. Anal fissures typically cause pain and bleeding with bowel movements. You also may experience spasms in the ring of muscle at the end of your anus (anal sphincter).
Signs and symptoms of an anal fissure include:
- Pain, sometimes severe, during bowel movements
- Pain after bowel movements that can last up to several hours
- Bright red blood on the stool or toilet paper after a bowel movement
- A visible crack in the skin around the anus
- A small lump or skin tag on the skin near the anal fissure
Common causes of anal fissure include:
- Passing large or hard stools
- Constipation and straining during bowel movements
- Chronic diarrhea
- Anal intercourse
You may be able to prevent an anal fissure by taking measures to prevent constipation or diarrhea. Eat high-fiber foods, drink fluids and exercise regularly to keep from having to strain during bowel movements.