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Anal fissure


An anal fissure is a small split or tear in the anal mucosa that may cause painful bowel movements and bleeding. There may be blood on the outside of the stool or on the toilet tissue following a bowel movement.


Anal fissures are extremely common in young infants but may occur at any age. Studies suggest 80% of infants will have had an anal fissure by the end of the first year. Most fissures heal on their own and do not require treatment, aside from good diaper hygiene. However, some fissures may require medical treatment.

The incidence of anal fissures decreases rapidly with age. Fissures are much less common among school-aged children than among infants.

In adults, fissures may be caused by constipation, the passing of large, hard stools, or by prolonged diarrhea. In older adults, anal fissures may be caused by decreased blood flow to the area.

Anal fissures are also common in women after childbirth and people with Crohn's disease.


  • Pain while having a bowel movement
  • Blood on the surface of stool (not mixed in with stool)
  • Blood on toilet tissue or wipes
  • A crack in the skin that is visible when the anus is stretched slightly (the fissure is almost always in the midline)
  • Constipation, often with painful bowel movements

Exams and Tests

  • Inspection of the rectum
  • Physical exam of the rectal mucosa


  • Stool softeners
  • Dietary adjustment (addition of bulk -- substances that absorb water while in the intestinal tract)
  • Cleansing more gently
  • Petroleum jelly
  • Sitz bath
  • Anesthetic ointment, if pain interferes with normal bowel movement
  • Topical muscle relaxants

These measures generally heal more than 90% of anal fissures.

For fissures that do not heal with these home treatments, injection of botulinum toxin (Botox) into the anal sphincter may be used to temporarily paralyze the anal sphincter muscle and promote healing. Another option for nonhealing fissures is a minor surgical procedure to relax the sphincter.

Outlook (Prognosis)

Anal fissures generally heal quickly without residual problems. However, people who develop fissures are more likely to have them in the future.

Possible Complications

Occasionally, a fissure becomes chronic and will not heal. Chronic fissures may require minor surgery to relax the sphincter.

When to Contact a Medical Professional

Call your health care provider if symptoms associated with anal fissure are present, or if the fissure does not heal appropriately with treatment.


To prevent anal fissures in infants, be sure to change diapers frequently.

To prevent fissures at any age:

  • Keep the anal area dry
  • Wipe with soft materials or a moistened cloth or cotton pad
  • Promptly treat any constipation or diarrhea
  • Avoid irritating the rectum

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