Anal fissure

The most common symptom of anal fissures is pain during or after passing a bowel motion (poo). Pain from anal fissure can cause anal muscle spasm and tightness, which worsens the problem.

Other symptoms include:

• blood on toilet paper. This may be the only symptom if the tear is mild.
• tearing sensation during bowel movements
• irritation or itching around the tear
• a small lump or skin tag around your anus.

Damage to the skin around your anus from over-stretching is the most common reason why an anal fissure develops. They can be caused by various factors such as:

• constipation (passing dry, hard poo, particularly if its large) or straining during bowel movements
• repeated diarrhoea (runny poo)
• pregnancy, childbirth and after delivery (postpartum period)
• sexually transmitted infections (STIs), particularly HIV, syphilis, and herpes simplex
• anal intercourse
• Crohn's disease, anal cancer, tuberculosis and chemotherapy (these are rarer causes).

When a fissure develops, the muscles inside the anus (internal anal sphincter) go into spasm which can cause further tearing and cutting off of blood flow making healing more difficult.

With proper treatment, an anal fissure is a curable problem and doesn't go on to form cancer.

If you have any of the symptoms above, you need to visit your doctor.

They will assess your symptoms and look at the skin around your anus to make a diagnosis. If there is an obvious fissure then usually a rectal exam is not required (inserting a gloved finger into the anus). If a fissure isn't visible but you have bleeding, and there is no obvious haemorrhoid to explain the bleeding, then they may arrange some tests such as a colonoscopy.

Most fissures can be treated simply and heal within a few weeks. Many fissures will heal on their own without medical treatment. However medical treatment increases the success rate.

Ease and prevent constipation

Soft stools will be less likely to open the fissure and cause pain. Increase the fibre in your diet by eating more vegetables, fruits, wholegrain breads and cereals. Learn more about fibre in your diet.(external link) 

You can also consider using commercially available fibre supplements such as psyllium (Metamucil and Konsyl D). These help by absorbing water into the stools (poo) in your bowel to soften them and improves the regularity of passing them. They are also called bulk forming laxatives. Learn more about bulk forming laxatives.

It's also important to drink at least 1.5 litres of fluid (ideally water) every day, unless your doctor advises you differently, eg, if you're elderly, or have kidney or heart failure. Using laxatives called stool softeners may also help to soften the poos. Read more about how to ease and prevent constipation.  

Avoid straining during bowel movements

You can place your legs on a short stool while on the toilet to help relax the muscles around the anus. You can also take regular sitz baths (sitting in warm water up to the hips) to ease the pain and relax these muscles.

Maintain good hygiene

It's important to keep your anal area clean by washing gently with water after passing a bowel motion. Make sure to wipe gently after going to the toilet.

Creams or ointments

Pain relief: To relieve pain and discomfort when passing poos, your healthcare provider may prescribe a local anaesthetic cream or ointment. Using this before going to the toilet can make it more comfortable to go.

If the above measures don't help, your doctor may prescribe a cream or ointment to help relax your anal muscles. They also allow more blood flow into the skin to enable the fissure to heal. It's important to continue treatment daily for 4 to 6 weeks to allow the fissure to heal adequately.

• Glyceryl trinitrate cream (Rectogesic): This is usually the first option. This is funded by Pharmac if the fissure has been present for more than 6 weeks. Read more about Rectogesic. 
• Diltiazem cream: This is another cream that could be prescribed. There's a charge for this as it isn't subsidised by the government.

Botox and surgery

Your surgeon could either give you an injection of Botox (botulinum toxin) or offer surgery. Surgery has the highest success rate of all treatments but has the highest risks and so is done as a last resort. The surgical options include making a small cut in your anal sphincter muscle (sphincterotomy), a skin flap (V-Y advancement flap), and cutting out the fissure (subcutaneous fissurectomy). The sphincterotomy is the procedure of choice for most people needing surgery.

For Botox and sphincterotomy, both methods relax the anal sphincter muscle, give pain relief and allow the fissure to heal. Sphincterotomy works best to manage anal fissure in the long-term compared to Botox but has a small risk of causing fecal incontinence (poo or gas leaking out unintentionally). Many people have mild incontinence immediately after surgery, but it's rarely permanent.

Some people are at high risk of incontinence after sphincterotomy, eg, if you've given birth to multiple children vaginally. In this instance your surgeon may recommend one of the other procedures.

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Anal fissures are not usually harmful or dangerous. However, some people (mainly children) may avoid having bowel movements due to fear of pain. This avoidance can lead to worsening constipation and increased straining during bowel movements, which makes the fissure worse or creates new fissures. To prevent this, it's important to address the underlying issues and encourage regular, pain-free bowel movements.

In rare cases, an infection or fistula can develop as a complication of an anal fissure. A fistula is an abnormal connection that forms between the inside of the rectum and the skin, creating a new channel. It's essential to seek medical attention if you suspect an infection or fistula, as they may require additional treatment to prevent further complications.