Patient education: Anal fissure (The Basics)

What is an anal fissure? — An anal fissure is a tear in the lining of the anus, the opening where your bowel movements come out (figure 1). Anal fissures cause pain, especially during a bowel movement.

There is a muscle that wraps around the anus and holds it shut. It is called the "anal sphincter." The sphincter gets tense when the anus is injured. In people with anal fissures, the sphincter goes into spasms, which can lead to further injury.

What causes anal fissures? — An anal fissure is most often caused by having a hard, dry bowel movement.

What are the symptoms of an anal fissure? — Most people who have an anal fissure feel a tearing, ripping, or burning pain when they have a bowel movement. This pain can last for hours. Some people also bleed slightly when they have a bowel movement. They might see bright red blood on the toilet paper or on the surface of the bowel movement. Some people with an anal fissure also have itching or irritation around the anus.

Should I see my doctor or nurse? — Yes. See your doctor or nurse if you bleed when you have a bowel movement.

Will I need tests? — Your doctor or nurse can check whether you have anal fissure by gently spreading your buttocks apart and looking at your anus.

If you have had bleeding, your doctor or nurse might send you for more testing after the fissure has healed. This involves a "sigmoidoscopy" or "colonoscopy" (figure 2). For these tests, the doctor puts a thin tube into your anus and up into your colon. The tube has a camera attached to it, so the doctor can look inside your colon and check for causes of bleeding.

How are anal fissures treated? — For the first month of treatment, doctors recommend trying to keep your bowel movements soft so they are easier to pass. To do this, you can:

●Take fiber supplements along with plenty of water. Supplements include:

•Psyllium (sample brand name: Metamucil)

•Methylcellulose (sample brand name: Citrucel)

•Calcium polycarbophil (sample brand name: FiberCon)

•Wheat dextrin (sample brand name: Benefiber)

●Take a stool softener if the fiber supplements are not enough. An example of a stool softener is docusate (sample brand name: Colace).

Your doctor can also prescribe a medicine that relaxes the anal sphincter muscle. This helps the fissure heal. The most commonly used medicine is nitroglycerin or nifedipine cream. Smear the cream around the fissure twice a day every day. It's important to keep doing this for as long as your doctor tells you to, even if you do not have pain every day. This will allow your fissure to heal completely.

You can also soak your buttocks in 2 or 3 inches of warm water. This is called taking a "Sitz bath." Sitz baths can help relieve pain by relaxing the sphincter. If you find that a Sitz bath helps, do it 2 to 3 times a day for 10 to 15 minutes. Do not add soap, bubble bath, or anything else to the water.

If these steps to do not work in 1 to 2 months, doctors can try other treatments, such as:

●Botulinum toxin ("BoTox") – This is a shot that can help the anal sphincter muscle relax and heal. It can help, but it can also cause short-term problems with leaking of gas or bowel movements.

●Surgery – During surgery, the doctor makes a small cut in the sphincter to help it relax. This surgery works in most patients, but doctors offer it only to people who do not get better with other treatments. Surgery can cause lasting problems with leaking of gas or bowel movements.

More on this topic

Patient education: High-fiber diet (The Basics)
Patient education: Constipation in adults (The Basics)
Patient education: Constipation in children (The Basics)
Patient education: Bloody stools in adults (The Basics)
Patient education: Bloody stools in children (The Basics)
Patient education: Colonoscopy (The Basics)
Patient education: How to take a sitz bath (The Basics)

Patient education: Anal fissure (Beyond the Basics)