Anal Fissures

Anal fissures are tears, or cracks, in your anus. Fissures result from the stretching of your anal mucosa beyond its normal capacity. Once the tear occurs, it leads to repeated injury. The exposed internal sphincter muscle beneath the tear goes into spasm. This causes severe pain. The spasm also pulls the edges of the fissure apart, making it difficult for your wound to heal. The spasm then leads to further tearing of the mucosa, when you have bowel movements. This cycle leads to the development of a chronic anal fissure in approximately 40 percent of patients. 

An acute anal fissure typically heals within six weeks, with conservative treatment. Some disappear when constipation is treated. Anal fissures that persist for six weeks or more are called chronic anal fissures. These fail conservative treatment and require a more aggressive, surgical approach.

Fissures are sometimes confused with hemorrhoids. These are inflamed blood vessels in, or just outside, the anus. Both fissures and hemorrhoids often result from passing hard stool.

You may have these symptoms with an anal fissure:

  • Pain during and after a bowel movement

  • Visible tear or cut in the area

  • Bright red bleeding during or after a bowel movement

Who’s at risk

Certain factors raise the risk for anal fissures, including:

  • Constipation with straining to pass hard stool

  • Eating a low-fiber diet

  • Intense diarrhea

  • Recent weight loss surgery, because it leads to frequent diarrhea

  • Vaginal childbirth

  • Minor trauma, especially trauma caused by high-level mountain biking

  • Any inflammatory condition of the anal area

Anal fissures may also result from inflammatory bowel disease, surgery, or other medical treatments that affect bowel movements or the anus.


Your doctor will make a diagnosis based on:

  • Your personal health history

  • Your description of symptoms

  • Rectal exam

Because other conditions can cause symptoms similar to an anal fissure, your doctor might also order tests to find out whether there is blood in your stool.


People whose anal fissures don’t heal well may have an imbalance in anal pressure that prevents blood from circulating normally through the blood vessels around the anus. The reduced blood flow prevents healing. Medication, Botox injections, and even some topical treatments that improve blood flow may help anal fissures heal.

Other treatments include:

  • Changing your diet to increase fiber and water, steps that will help regulate your bowel movements and reduce both diarrhea and constipation

  • Taking warm baths for up to 20 minutes a day

  • Taking stool softeners such as fiber supplements, as needed

  • Taking medications such as nitrates or calcium blockers

  • Having surgery, such as a lateral internal sphincterectomy. During the surgery, the pressure inside the anus is released, allowing more blood to flow through the area to heal and protect tissues.

The risks from Botox injections and medications used to treat anal fissures are relatively mild. Complications from surgery include the risk for infection, bleeding, and persistent gas and fecal incontinence, or uncontrolled bowel movements.


Complications seen with anal fissures include:

  • Pain and discomfort

  • Reduced quality of life

  • Difficulty with bowel movements, especially because many people avoid going to the bathroom because of the pain and discomfort it causes

  • Possible recurrence even after treatment

  • Clotting

  • Uncontrolled bowel movements and gas

Preventing and living with anal fissures

If you have an anal fissure, take these precautions to avoid making it worse and avoid recurrences:

  • Take all medicines as prescribed.

  • Get the recommended amount of fiber in your diet.

  • Drink enough water to stay well hydrated.

  • Maintain a routine bowel habit. Ask your doctor about what this should be for you.

  • Avoid spicy foods while you have an anal fissure, because they may make symptoms worse. 

When to call the doctor

Contact your doctor if you notice blood in your stool or if your bowel movements are so painful that you are avoiding going to the bathroom.