Note: All links within content go to MayoClinic.com

An anal fissure is a small tear in the lining of the anal canal. Common in infants ages 6 to 24 months, anal fissures are less likely to develop in older children. Adults may develop anal fissures as a result of passing hard or large stools during bowel movements.

Anal fissures may cause pain and bleeding. More than 90 percent heal on their own, and you can use topical creams or suppositories to provide relief as they heal. Anal fissures that fail to heal may become chronic and cause considerable discomfort.

If you develop an anal fissure that fails to heal, surgery may relieve your discomfort.

The main signs and symptoms of an anal fissure include:

• Pain or burning during bowel movements that eases until the next bowel movement
• Bright red blood on the outside of the stool or on toilet paper or wipes after a bowel movement
• Itching or irritation around the anus

The most common cause of anal fissures is large or hard stool passing through the anal canal during bowel movements. Other causes include:

• Constipation and straining during bowel movements
• Inflammation of the anorectal area, such as is caused by inflammatory bowel disease (IBD)
• Anal sex (rarely)

Factors that increase your risk of developing an anal fissure include:

• Infancy. As many as 80 percent of infants experience an anal fissure during their first year of life, although experts aren't sure of the reason.
• Old age. Older adults may develop an anal fissure partly because of slowed circulation, resulting in decreased blood flow to the rectal area.
• Constipation. Straining during bowel movements and passing hard stools increase the risk of tearing.
• Childbirth. Anal fissures are more common in women after they give birth.
• Crohn's disease. This inflammatory bowel disease causes chronic inflammation of the intestinal tract, which may make the lining of the anal canal more vulnerable to tearing.

See your doctor if you have pain during bowel movements or blood on stools or toilet paper after a bowel movement.

Your doctor will ask you for your medical history and perform a physical exam, including inspection of the anal region. In many cases of anal fissure, the tear is visible.

Your doctor is likely to refrain from performing a rectal exam, which involves inserting a gloved finger or a small instrument into your anal canal, because it may cause pain.

However, after your anal fissure has healed and especially if you've had rectal bleeding, your doctor may recommend further testing, usually a sigmoidoscopy or colonoscopy, to be sure no underlying disorder, such as Crohn's disease, caused your anal fissure. Both tests involve inserting a thin, flexible tube into your rectum. A tiny video camera allows your doctor to see inside your rectum and colon.

If you're 50 or older, your doctor likely will recommend a colonoscopy, which allows viewing of the entire colon and also serves as a screen for colorectal cancer, another possible cause of rectal bleeding. If you're younger than 50 and have no risk factors for intestinal diseases or colon cancer, your doctor may recommend the less invasive sigmoidoscopy, which allows viewing of only the bottom portion of the colon.

Anal fissures rarely cause complications. If a fissure fails to heal, it may become chronic, which means it's present for more than six weeks. Once an anal tear occurs, it may happen again, leading to repeated injury of the tissue.

The tear occasionally may go into your internal anal sphincter, a ring of muscle that holds your anus closed except during bowel movements. A tear in the muscle usually causes the muscle to spasm, which widens the tear and hampers healing. An unhealed fissure can result in a cycle of discomfort that may require surgery to reduce the pain and repair or remove the fissure.

Anal fissures are fairly common and usually heal without treatment or with nonsurgical treatments. Signs and symptoms may go away within two weeks, but it may take up to eight weeks for the tear to heal. If the tear doesn't heal within six to eight weeks, however, you may need surgery.

For infants, the only intervention necessary may be changing the diaper regularly and keeping the anal area clean. Discuss with your pediatrician ways to avoid constipation and ensure regular bowel movements to prevent your baby from straining.

Nonsurgical treatments
If lifestyle and self-care measures such as adding more fiber to your diet, drinking more water, getting regular exercise, and taking a stool softener or occasional laxative aren't effective, your doctor may recommend the following nonsurgical treatments:

• Medicated creams or suppositories. Your doctor may prescribe a rectal corticosteroid (Anusol, others) or recommend an over-the-counter cream or ointment containing hydrocortisone Cortaid, Preparation H) to help reduce inflammation and ease discomfort.

• Other nonsurgical therapies. Some doctors recommend applying nitroglycerine ointment to the anus, which widens blood vessels and increases blood flow to the tear, promoting healing. This fairly new therapy also helps reduce pressure in the anal sphincter, which eases the spasm and decreases pain, both of which promote healing. The dose of nitroglycerine is small to avoid dangerous side effects. However, it may cause side effects such as headaches, low blood pressure and dizziness. Men shouldn't use nitroglycerine within 24 hours of taking erectile dysfunction medications such as sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra) because of the possibility of significantly lowered blood pressure.

  Another fairly new treatment involves injecting a small dose of botulinum toxin type A (Botox) into the internal anal sphincter. Botox paralyzes the muscle for up to three months, causing the spasm to relax. A possible side effect is temporary, mild leakage of gas or stool (anal incontinence).

  Both topical nitroglycerine and Botox have shown promise in relieving anal fissures in most studies. Researchers are testing these treatments alone and in combination with other drugs. Blood pressure medications nifedipine (Adalat) and diltiazem (Cardizem), taken orally or ground into a gel and applied to the tear, also have shown some promise.

Surgery
If you have a chronic anal fissure that won't heal on its own, your doctor may recommend surgery. Surgery usually involves cutting a portion of the anal sphincter muscle to reduce spasm and pain and promote healing. Surgery may also include removal of the fissure and any scar tissue resulting from it.

Adults usually have outpatient surgery. Children who have surgery may need to stay overnight in the hospital. Rarely, cutting the anal sphincter results in loss of ability to control bowel movements.

You may be able to prevent an anal fissure by taking measures to prevent constipation. Eat high-fiber foods, drink fluids and exercise regularly to keep from having to strain during bowel movements.

The following lifestyle changes may help relieve discomfort and promote healing of an anal fissure, as well as prevent recurrences:

• Add fiber to your diet. You can increase your fiber intake by eating more fruits, vegetables, nuts and whole grains. The recommended amount of fiber is 20 to 35 grams a day. Most people don't get that much, so you may want to take a fiber supplement. Bulk-forming laxatives, such as psyllium (Fiberall, Metamucil, others), soften stools and allow them to pass more easily. Adding fiber through either diet or supplementation may cause gas and bloating, so increase your fiber intake gradually.
• Drink adequate fluids. Fluids also help prevent constipation, so it's important to get enough. However, it may be difficult to determine how much is enough for you. If you're rarely thirsty and your urine looks dilute (colorless or very light yellow), you're probably drinking enough.
• Exercise regularly. You can experience a host of benefits by walking or engaging in 30 minutes of another moderate activity most days of the week. Among those benefits are promoting regular bowel movements and increasing blood flow to all parts of your body, which may promote healing of an anal fissure.
• Take a sitz bath. Soaking in warm water for 15 to 30 minutes one or more times a day, especially after bowel movements, will help ease pain and itching.
• Avoid straining during bowel movements. Straining creates pressure, which can open a healing tear or cause a new tear.