An anal fissure is a small tear in the thin, moist tissue (mucosa) that lines the anus. An anal fissure may occur when you pass 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 (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 increased fiber intake or sitz baths. Some people with anal fissures may need medication or, occasionally, surgery.
Signs and symptoms of an anal fissure include:
- Pain, sometimes severe, 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 on the skin near the anal fissure(sentinel tag)
When to see a doctor
See your doctor if you have pain during bowel movements or notice blood on stools or toilet paper after a bowel movement.
Common causes of anal fissure include:
- Passing large or hard stools
- Constipation and straining during bowel movements
- Chronic diarrhea
- Anal intercourse
Less common causes of anal fissures include:
- Crohn’s disease or another inflammatory bowel disease
- Anal cancer
Factors that may increase your 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, which 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 anal fissure can 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 your anus closed (internal anal sphincter), making it more difficult for your anal fissure to heal. An unhealed fissure can trigger a cycle of discomfort that may require medications or surgery to reduce 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.
Your doctor will likely ask about your 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.
An acute anal fissure looks like a fresh tear, somewhat like a paper cut. A chronic anal fissure likely has a deeper tear, and 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 sign of another disorder, such as Crohn’s disease. Your doctor may recommend further testing if he or she thinks you have an underlying condition:
- Anoscopy. An anoscope is a tubular device inserted into the anus to help your doctor visualize the rectum and anus.
- Flexible sigmoidoscopy. Your doctor will insert a thin, flexible tube with a tiny video into the bottom portion of your colon. This test may be done if you’re younger than 50 and have no risk factors for intestinal diseases or colon cancer.
- Colonoscopy. Your doctor will insert a flexible tube into your rectum to inspect the entire colon. This test may be done if you are older than age 50 or you have risk factors for colon cancer, signs of other conditions, or other symptoms such as abdominal pain or diarrhea.
Anal fissures often heal within a few weeks if you take steps to keep your stool soft, such as increasing your intake of fiber and fluids. Soaking in warm water for 10 to 20 minutes several times a day, especially after bowel movements, can help relax the sphincter and promote healing.
If your symptoms persist, you’ll likely need further treatment.
Your doctor may recommend:
- Externally applied ointment, to help increase blood flow to the fissure and promote healing and to help relax the anal sphincter. Nitroglycerin is generally considered the medical treatment of choice when other conservative measures fail. Side effects may include headache, which can be sometimes severe.
- Topical anesthetic creams such as lidocaine hydrochloride (Xylocaine) may be helpful for pain relief.
- Botulinum toxin type A injection, to paralyze the anal sphincter muscle and relax spasms.
- Blood pressure medications, such as oral nifedipine or diltiazem can help relax the anal sphincter. These medications may be taken by mouth or applied externally and may be used when nitroglycerin is not effective or causes significant side effects.
If you have a chronic anal fissure that is resistant to other treatments, or if your symptoms are severe, your doctor may recommend surgery. Doctors usually perform a procedure called lateral internal sphincterotomy (LIS), which involves cutting a small portion of the anal sphincter muscle to reduce spasm and pain, and promote healing.
Studies have found that for chronic fissure, surgery is much more effective than any medical treatment. However, surgery has a small risk of causing incontinence.
Lifestyle and home remedies
Several lifestyle changes may help relieve discomfort and promote healing of an anal fissure, as well as prevent recurrences:
- Add fiber to your diet. Eating about 25 to 30 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.
- Drink adequate fluids. Fluids help prevent constipation.
- Avoid straining during bowel movements. Straining creates pressure, which can open a healing tear or cause a new tear.
If your infant has an anal fissure, be sure to change diapers frequently, wash the area gently and discuss the problem with your child’s doctor.