An anal fissure is a small tear in the thin, moist tissue that lines the anus. The anus is the opening at the end of the digestive tract where stool exits the body. Common causes of an anal fissure include constipation and straining or passing hard or large stools during a bowel movement. Anal fissures typically cause pain and bleeding with bowel movements. You also may experience spasms in the ring of muscle at the end of your anus, called the anal sphincter.

Anal fissures are very common in young infants but can affect people of any age. Most anal fissures get better with simple treatments, such as eating more fiber or soaking in a warm-water bath. Some people with anal fissures may need medicine. Sometimes, surgery may be necessary.

Symptoms of an anal fissure include:

• Pain during bowel movements.
• Pain after bowel movements that can last up to several hours.
• Bright red blood on the stool or toilet paper after a bowel movement.
• A visible crack in the skin around the anus.
• A small lump or skin tag near the anal fissure.

When to see a doctor

See a healthcare professional if you have pain during bowel movements or notice blood on stools or toilet paper after a bowel movement.

Common causes of anal fissures include:

• Passing large or hard stools.
• Constipation and straining during bowel movements.
• Long-lasting diarrhea.
• Anal intercourse.
• Childbirth.

Less common causes of anal fissures include:

• Crohn's disease or another inflammatory bowel disease.
• Anal cancer.
• HIV.
• Tuberculosis.
• Syphilis.

Factors that may increase the risk of developing an anal fissure include:

• 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. This may make the lining of the anal canal more vulnerable to tearing.
• Anal intercourse.
• Age. Anal fissures can occur at any age, but are more common in infants and middle-aged adults.

Complications of an anal fissure may include:

• Failure to heal. An anal fissure that fails to heal within eight weeks is considered chronic and may need further treatment.
• Recurrence. Once you've experienced an anal fissure, you are prone to having another one.
• A tear that extends to surrounding muscles. An anal fissure may extend into the ring of muscle that holds the anus closed. This muscle is called the internal anal sphincter. If this happens, it makes it more difficult for the anal fissure to heal. An unhealed fissure may trigger a cycle of discomfort that may require medicines or surgery to ease the pain and to repair or remove the fissure.

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

A healthcare professional will likely ask about medical history and perform a physical exam, including a gentle inspection of the anal region. Often the tear is visible. Usually, this exam is all that's needed to diagnose an anal fissure.

A more recent, acute anal fissure looks like a fresh tear, somewhat like a paper cut. A long-lasting, also called chronic, anal fissure likely has a deeper tear. It also may have internal or external fleshy growths. A fissure is considered chronic if it lasts more than eight weeks.

The fissure's location offers clues about its cause. A fissure that occurs on the side of the anal opening, rather than the back or front, is more likely to be a symptom of another condition, such as Crohn's disease. A medical professional may recommend further testing to find out if there is an underlying condition. Tests may include:

• Anoscopy. An anoscope is a tubular device inserted into the anus to help see the rectum and anus.
• Flexible sigmoidoscopy. In this test, a thin, flexible tube with a tiny camera attached is inserted into the bottom portion of the colon. This test may be done for people younger than 45 who have no risk factors for intestinal diseases or colon cancer.
• Colonoscopy. This test involves inserting a flexible tube into the rectum to inspect the entire colon. Colonoscopy may be done for someone who:
  • Is older than age 45.
  • Has risk factors for colon cancer.
  • Has symptoms of other conditions.
  • Has other symptoms, such as stomach pain or diarrhea.

Anal fissures often heal within a few weeks with appropriate home treatment. Take steps to keep the stool soft, such as increasing your intake of fiber and fluids. Soak in warm water for 10 to 20 minutes several times a day, especially after bowel movements. This can help relax the sphincter and promote healing. If symptoms persist, you'll likely need further treatment.

Nonsurgical treatments

A healthcare professional may recommend the following:

• Externally applied nitroglycerin (Rectiv) can help increase blood flow to the fissure and promote healing. It also can help relax the anal sphincter. Nitroglycerin is generally considered the treatment of choice when other conservative measures fail. Side effects may include headache, which can be severe.
• Topical anesthetic creams such as lidocaine (Xylocaine) may help relieve pain.
• OnabotulinumtoxinA (Botox) injection paralyzes the anal sphincter muscle and relaxes spasms.
• Blood pressure medicines, such as nifedipine or diltiazem, help relax the anal sphincter. These medicines are generally applied to the skin but also can be taken by mouth. However, when taken by mouth, their side effects can be greater. These medicines may be used when nitroglycerin is not effective or causes serious side effects.

Surgery

If you have a chronic anal fissure that is resistant to other treatments, or if your symptoms are severe, surgery may be recommended. Surgeons usually perform a procedure called lateral internal sphincterotomy (LIS). LIS involves cutting a small part of the anal sphincter muscle. This technique may help promote healing and reduce spasm and pain.

Studies show that surgery is much more effective than any medical treatment for chronic fissure. However, surgery has a small risk of causing incontinence.

Several lifestyle changes may help relieve discomfort and promote healing of an anal fissure, as well as prevent one from coming back. Changes include:

• Adding fiber to your diet. Eating about 25 to 35 grams of fiber a day can help keep stools soft and improve fissure healing. Fiber-rich foods include fruits, vegetables, nuts and whole grains. You also can take a fiber supplement. Adding fiber may cause gas and bloating, so increase your intake gradually.
• Drinking adequate fluids. Fluids help prevent constipation.
• Not straining during bowel movements. Straining creates pressure, which can open a healing tear or cause a new tear.
• Sitting in a warm bath. Also called a sitz bath, soaking in a warm-water bath for 10 to 20 minutes several times a day can soothe the skin and promote relaxation. If possible, take a sitz bath after bowel movements.

If your infant has an anal fissure, change diapers often and wash the area gently. Also, be sure to discuss the problem with your child's healthcare team.

If you have an anal fissure, you may be referred to a doctor who specializes in digestive diseases, called a gastroenterologist, or a colon and rectal surgeon.

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do in advance, such as fasting before having a specific test. Before your appointment:

• Make a list of your symptoms, even if they may seem unrelated to the reason for your appointment.
• Write down key personal information, including major stresses, recent life changes and family medical history.
• Bring a list of all medicines, vitamins or other supplements you take, including the doses.
• Bring someone with you. If possible, bring a family member or friend with you to help remember things you may forget.
• Prepare questions to ask during your appointment.

Some basic questions to ask include:

• What is likely causing my symptoms?
• Are there any other possible causes for my symptoms?
• Do I need any tests?
• Is my condition likely temporary or chronic?
• Are there any dietary suggestions I should follow?
• Are there restrictions I need to follow?
• What's the best course of action?
• What are the alternatives to the primary approach you're suggesting?
• I have these other health conditions. How can I best manage them together?
• Are there brochures or other printed material I can have? What websites do you recommend?

Don't hesitate to ask other questions during your appointment.

What to expect from your doctor

You may be asked:

• When did you begin experiencing symptoms?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• Where do you feel your symptoms the most?
• Does anything seem to improve your symptoms?
• What, if anything, seems to worsen your symptoms?
• Do you have any other medical conditions, such as Crohn's disease?
• Do you have problems with constipation?

What you can do in the meantime

While you're waiting to see your healthcare professional, take steps to avoid constipation, such as:

• Drinking plenty of water.
• Adding fiber to your diet.
• Exercising regularly.

Also, don't strain during bowel movements. The extra pressure may lengthen the fissure or create a new one.