Anal fissure

What are anal fissures?

Anal fissures are small tears or cracks on the part of the anus that opens when you pass stools— where the inside of the anus meets the outside. They are associated with pain and bleeding during bowel movements. Most will heal on their own and do not require treatment.

Illustration of an anal fissure

What causes anal fissures?

In adults they can be caused by passing a large, hard stool, or by having frequent diarrhea. In older adults they may occur due to decreased blood flow to the area. Having too much tension in your sphincter muscle or having anal intercourse may also cause anal fissures.

Who’s most likely to get anal fissures?

Anal fissures are common in those with chronic constipation or diarrhea. They are also common in women after child birth and in people with Crohn’s disease. If you’ve already had an anal fissure, you’re more likely to get one again.

Anal fissures in infants

Anal fissures are a common cause of drops of red blood on a baby’s diaper. However, if your infant has blood in their diaper you should take them to visit a doctor.


The symptoms of anal fissures can vary depending on the severity of the crack or tear.

They may include

  • Minor rectal bleeding
  • Severe pain during bowel movements
  • Throbbing anal spasm/pain after bowel movements
  • Small amounts of red blood on toilet paper or stool
  • A lump or skin tag near the anal fissure
  • Constipation


Your doctor will most likely determine if you have anal fissures by performing a physical exam. They can generally be seen by gently spreading your butt cheeks. Typically, digital rectal exams and anoscopies are not performed if a fissure is seen. If you have frequent anal fissures due to chronic diarrhea or constipation, your doctor may want to perform additional tests.

These could include

  • Colonoscopy- A small device with a camera is inserted in your colon to look for abnormalities.
  • Sigmoidoscopy- This is similar to a colonoscopy, but only examines the lower part of the large intestine.
  • Anoscopy- With a scope (a small tube with a camera) your doctor can see inside your anus and lower rectum.
  • Biopsy- During any of the previously listed exams, your doctor may have the option to take a tissue sample for testing.


How to treat your anal fissure at home

You can treat anal fissures with a zinc oxide ointment to reduce discomfort. A bath that covers your hips and buttocks may also be helpful. Sitting in a bath 2-3 times a day for 10-20 minutes will relax the area and reduce discomfort. This is especially recommended after passing a stool. Epson salts can be added to the bath every so often to relieve irritation.

Adding a fiber powder to your diet and drinking more water can help ease discomfort while passing stools. Many different over-the-counter fiber powders are available. You should also consume at least 64oz of water daily and minimize caffeine. Having softer stools will eliminate the need to strain during bowel movements and will promote the healing of anal fissures. If necessary, make lifestyle changes to maintain healthy bowel habits.

Lifestyle changes

Increasing the fiber in your diet and drinking more water can ease straining that leads to anal fissures. Fiber supplements can also help soften stools. Prevent constipation by exercising regularly and consuming a healthy diet with plenty of water. If you have severe constipation or diarrhea, talk to your doctor about additional treatment options.

Additional treatment for anal fissures

Your doctor can give you medicine to relax your anal muscles. Surgery is also an option for chronic cases. Injecting Botox into the area can temporarily paralyze the sphincter muscle and relieve anal tension. An operation called a lateral internal sphincterectomy can also be performed to help relax the sphincter muscle. Surgery tends to be very effective in preventing anal fissure reoccurrence.

When to see a doctor

If you have bothersome symptoms of anal fissures or an anal fissure that won’t seem to heal, visit your doctor. They can find the cause of your anal fissures and give you a specialized treatment plan.

Last reviewed: 
July 2018

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