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What is an anal fissure?
An anal fissure is a tear in the lining of the lower rectum (anal canal) that causes pain during bowel movements. Anal fissures don't lead to more serious problems.
Most anal fissures heal with home treatment after a few days or weeks. These are called short-term (acute) anal fissures. If you have an anal fissure that hasn't healed after 8 to 12 weeks, it is considered a long-term (chronic) fissure. A chronic fissure may need medical treatment.
Anal fissures are a common problem. They affect people of all ages, especially young and otherwise healthy people.
What causes an anal fissure?
Anal fissures are caused by injury or trauma to the anal canal. Injury can happen when:
- You pass a large stool.
- You are constipated and try to pass a hard stool.
- You have repeated diarrhea.
- You give birth. (Childbirth can cause trauma to the anal canal.)
Fissures can also be caused by a rectal examination, anal intercourse, or a foreign object. In some cases, a fissure may be caused by Crohn's disease.
Many experts believe that extra tension in the two muscular rings (sphincters) controlling the anus may be a cause of fissures. The outer anal sphincter is under your conscious control. But the inner sphincter is not. This muscle is under pressure, or tension, all of the time. If the pressure increases too much, it can cause spasm and reduce blood flow to the anus, leading to a fissure. This pressure can also keep a fissure from healing.
What are the symptoms?
You may have:
- A sharp, stinging, or burning pain during bowel movements. Pain from a fissure may be quite severe. It can be brief or last for several hours after a bowel movement.
- Bleeding. You may see a small spot of bright red blood on toilet tissue or a few drops in the toilet bowl. The blood from a fissure is separate from the stool. (Very dark, tarry stools or dark red blood mixed with stool may be a sign of a more serious problem.) Tell your doctor if you have any bleeding with a bowel movement.
Sometimes an anal fissure may be a painless wound that won't heal. It may bleed from time to time but cause no other symptoms.
How is an anal fissure diagnosed?
A doctor can diagnose an anal fissure based on your symptoms and a physical examination. The examination may include:
- Looking at the fissure by gently separating the buttocks.
- A digital rectal examination. The doctor inserts a gloved finger into the anal canal.
- Anoscopy. This involves using a short, lighted scope to look into the anal canal.
The doctor may wait until the fissure has started to heal before doing a rectal examination or anoscopy. If an examination needs to be done right away, medicine can be used to numb the area.
During an examination, a doctor can also find out whether another condition may be causing the fissure. Having several fissures or having one or more in an area of the anus where fissures usually don't occur can be a sign of a more serious problem, such as inflammatory bowel disease or a weakened immune system.
How is it treated?
Most short-term anal fissures can heal with home treatment in 4 to 6 weeks. Pain during bowel movements usually goes away within a couple of days after the start of home treatment.
There are several steps you can take to relieve your symptoms and help the fissure heal:
- Try to prevent constipation. For example:
- Include fruits, vegetables, beans, and whole grains in your diet each day. These foods are high in fibre.
- Drink plenty of fluids.
- Get some exercise every day.
- Take a fibre supplement, such as Benefibre or Metamucil, every day if needed. Read and follow all instructions on the label.
- Use the toilet when you feel the urge. Or when you can, schedule time each day for a bowel movement. A daily routine may help. Take your time and do not strain when having a bowel movement. Do not sit on the toilet too long.
- Try taking stool softeners or laxatives to make bowel movements less painful. Ask your doctor how long you should take laxatives.
- Sit in a tub filled with a few centimetres of warm water for 20 minutes, 2 or 3 times a day. This is called a sitz bath. It soothes the torn tissue and helps relax the internal anal sphincter. Do not put soaps, salts, or shampoos in the water.
- Talk with your doctor about whether to try a non-prescription cream such as zinc oxide, Preparation H, Anusol, or hydrocortisone for a short time. These may help soothe anal tissues. But fibre and sitz baths help symptoms more.footnote 1
- Be safe with medicines. Read and follow all instructions on the label. If the doctor gave you a prescription medicine for pain, take it as prescribed. If you are not taking a prescription pain medicine, ask your doctor if you can take an over-the-counter medicine.
- Instead of using toilet paper, use baby wipes or medicated pads, such as Preparation H or Tucks, to clean after a bowel movement.
Don't avoid having bowel movements. Knowing that it might hurt may make you anxious. But trying not to have bowel movements will only make constipation worse and keep the fissure open and painful.
What happens if the fissure doesn't heal on its own?
About 9 out of 10 short-term fissures heal with home treatment—including using stool softeners or fibre supplements and taking regular sitz baths. And about 4 out of 10 long-term anal fissures will heal after home treatment is used.footnote 1
But not all fissures will heal with just home treatment. If a fissure lasts more than 8 to 12 weeks, you may need prescription medicines. These may include nitroglycerin cream, high blood pressure medicines in pill or gel form, or injections of botulinum toxin (Botox).
If medicines don't stop your symptoms, you may need to consider surgery. The most commonly used surgery is lateral internal sphincterotomy. In this procedure, a doctor cuts into part of the internal sphincter to relax the spasm that is causing the fissure.
- Dozois EJ, Pemberton JH (2006). Anal fissure section of Hemorrhoids and other anorectal disorders. In MM Wolfe et al., eds., Therapy of Digestive Disorders, pp. 948–950. Philadelphia: Elsevier.
Current as of:
April 15, 2020
Author: Healthwise Staff
Anne C. Poinier MD - Internal Medicine
Adam Husney MD - Family Medicine
E. Gregory Thompson MD - Internal Medicine
C. Dale Mercer MD, FRCSC, FACS - General Surgery
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