An anal fissure is a small tear in the thin, moist tissue (mucosa) that lines the anus. Anal fissures can occur as a result of passing hard or large stools during a bowel movement.

Anal fissures are common in infants but can occur in people of any age. A fissure usually heals on its own within 4 to 6 weeks. On the other hand, if the anal fissure does not resolve on its own, treatment or surgery options are available to relieve the discomfort.


The symptoms of an anal fissure include:

  • Pain (often severe) during bowel movements
  • Pain after bowel movement that can last for hours
  • Blood in the stool after bowel movements
  • Spasms in the anal sphincter
  • Itching or irritated anus
  • Crack in the skin around the anus
  • A small lump on the skin near the anal fissure


The common causes of anal fissure include:

  • Passing hard or large stools
  • Constipation and straining during bowel movements
  • Chronic diarrhea
  • Childbirth
  • Inflammation of the anorectal area caused by an inflammatory bowel disease such as Crohn’s disease.

Some of the less common causes of anal fissures are:

  • Anal cancer
  • HIV
  • Tuberculosis
  • Herpes
  • Syphilis

Risk factors

The following factors increase the risk of an anal fissure:

  • Infancy: Many infants develop anal fissures during the first year of life.
  • Aging: Older people have slowed circulation that decreases the blood flow to the rectal area, which may result in an anal fissure
  • Constipation: Straining during bowel movements and passing hard stools increase the risk of developing an anal fissure.
  • Childbirth: Anal fissures commonly occur in women after childbirth.
  • Crohn’s disease: Crohn’s disease causes chronic inflammation of the intestinal tract making the lining of the anal canal more vulnerable.


Anal fissures can give rise to some complications including:

  • Failure to heal: Anal fissures that fail to heal within six weeks is chronic thus further treatment is necessary.
  • Recurrence: Once an anal fissure occurs the person is more prone to developing another in the future.
  • A tear extending to surrounding muscles: An anal fissure may expand into the internal anal sphincter (the ring of muscle that holds the anus closed) causing difficulties in the healing process. In this case, medications or surgery may be used to relieve pain and repair the fissure.


Preventing constipation can prevent an anal fissure. Consuming high-fiber foods, lots of fluids and regular exercises lessen the strain during bowel movements.