Skip to main content

Everything you need to know about anal fissures (12 mins)


In a nutshell:

1. Pain with bowel motions is never normal. There is almost always a medical cause. You should see a doctor.

2. Fissures are the most common cause of pain while pooping amongst working age adults

3. Fissures are a two part problem – initial damage to the perianal skin, and muscle spasm causing reduced blood flow and preventing healing of the original damage

4. To treat fissures, you need to prevent further damage to the perianal skin by regulating your bowels. Your doctor can help treat the muscle spasm by creams, botox injections or surgery to heal the damage. Once the damage is healed, your pain will go away.

For the longer version, read on…

Why does it hurt when I poop, and what should I do?

Pain with pooping is never normal. Almost always it suggests that there is damaged skin somewhere near your anus. It is tricky to figure out what has caused the damage, and you will almost always want a professional to examine your bottom and figure out what is going on.

The 3 main causes your doctor will want to differentiate between are:

  • Fissures
  • Thrombosed haemorrhoids
  • Excoriated Skin

They will also want to rule out anal cancer because while that is almost never painful, if it is the cause, it is important to get it treated as quickly as possible.

How do I know if I have a fissure?

It can be tricky to self diagnose, as it is hard to see the area. The usual symptoms are bright red blood on wiping, and a razor blade type pain when you use your bowels. Because there is an overlap in symptoms with haemorrhoids, there is often confusion between the two.

This patient has two fissures. One is visible (top), the other (bottom) suggested by the lump called a ‘sentinel tag’.

As you can see, it’s pretty subtle, and if you don’t know what you’re looking for, you’re likely to call it the wrong thing. To make the diagnosis for certain, you should see your doctor. In general the younger you are (teens and 20’s), the more likely you are to have a fissure not haemorrhoids as a cause of pain and bleeding from the butt.

What causes fissures?

There are 2 important parts to a fissure – the initial injury, and the muscle spasm that prevents healing.

In short, fissures are breaks in the lining of the anal canal caused by trauma of some kind. Typically this is a constipated hard stool, but could also be explosive diarrhoea, trauma or surgery to the anal canal like having haemorrhoids removed.

The butt is a sensitive area, so a small injury like a fissure can cause a lot of pain. One of the body’s natural reflex responses to pain is muscle spasm. For example, if you injure your back, the body responds with muscle spasm to keep the tissues stiff and still, and let it heal. In fissures, it’s the internal anal sphincter that spasms.

Spasm is the reason fissures don’t heal, because blood flow to the area becomes reduced. This perpetuates the pain-spasm cycle.


Doctors have learnt (by trial and error) that relieving spasm is the best way to heal fissures. It is important to remember that the spasm is a reflex and not under your conscious control. Whilst many fissures do heal by themselves in the early stages, once the pain-spasm cycle is firmly established, anti spasm treatment is required to heal the fissure. Fissures lasting beyond six weeks are less likely to heal without treatment.

How are fissures treated?

All of the effective fissure treatments work by relieving spasm. The only difference between them is how long the anti spasm effect lasts for.

As a starting point, regulating bowel function into the Goldilocks zone of passing a single, formed, play dough consistency stool is best. For the average western diet, this means taking a fibre supplement of some kind like psyllium.

Treatments for fissures come in three forms; Creams, Botox and Surgery.


How do creams work? These creams contain medications that relax the internal sphincter muscle, restoring blood flow and allowing the fissure to heal. Typically each application of these creams will last six or eight hours and when used regularly will heal ⅔ of fissures in six weeks. The downside is their side effects.

Rectogesic is a prescription-only, “off-the-shelf” cream that contains GTN (Glyceryl Trinitrate), a medication traditionally used for angina (heart pain) and hypertension (high blood pressure). It works by relaxing the involuntary continence muscle (the internal sphincter). Unfortunately, because it is absorbed into the body, it can cause a throbbing headache as well as dizziness when standing up (postural hypotension) as side effects.

Diltiazem and nifedipine are re-purposed blood pressure medications and also work by reducing spasm, but by a different mechanism. They aren’t available “off-the-shelf” in Australia, but may be in other countries. Your doctor or pharmacist will be able to check this for you. Because they are less likely to cause side effects, they are also likely to be more effective because they are more likely to be consistently used. The downside of not being “off-the-shelf” is that a compounding pharmacy needs to mix it up. This means there can be differences from batch to batch, and different pharmacies might use different additives which may affect the effectiveness of the medication.

Botox injections (yes the same that are used for wrinkle treatment) are used because the botulinum toxin causes muscle paralysis and reduces spasm. A small dose of botox is injected into the internal sphincter. Only a little bit of the sphincter has to relax to improve the blood flow enough to heal the fissure. The advantage over creams is that the effect lasts for up to 12 weeks. The downside is the injections are expensive, and at the moment must be administered by needle. Most commonly, this is performed under general anaesthetic, which requires a hospital admission, and this further increases the wait times and cost of treatment. Effectiveness for one injection is said to be around 75%.

Surgery has the advantage of being 99% effective, but again requires an anaesthetic, and the effect is permanent. The procedure is usually called a ‘lateral internal sphincterotomy’ and this involves cutting part of the continence muscle (usually about 5mm worth). The side effect is a theoretical increase in incontinence especially with age. In practice, because of the differing anatomy in males and females, it is used as a good option for resistant fissures in males. Males usually have a 30-35mm continence muscle, so cutting 5mm rarely causes long term problems. In females however, the muscle is shorter (25mm) and the effect of childbirth and menopause can reduce continence. It is therefore offered sparingly in females, because the rate of continence problems is so high anyway.


Just as some people sunburn or tan differently, healing responses vary in humans. This means that some people are prone to fissuring repeatedly, either because they have erratic bowel function or an exaggerated muscle spasm response. What usually happens is that once a person understands the the way fissures work, they institute treatment earlier, and are better at regulating their own bowels, with diet modification, or the addition of fibre supplementation, preventing the flywheel of pain causing spasm which prevents healing from spinning up.

There are a group of patients with very resistant fissures, who require surgery to permanently cut part of the muscle. Whilst this almost always heals the fissure, there is a small associated risk of future incontinence.

The promotional bit.
At we have a mission:
Alleviate, Educate and Liberate.

With that in mind, for fissures, we are working on a few projects under the code-name “Fiss Off”, and if you like what you see, we’d love it if you could show your support. We would like to do the necessary research to prove that this combination of medications is superior to existing “off-the-shelf” options and get this mix of medications approved by the relevant regulatory agencies. If you’re interested in helping out in some way with the development, join our tester program.

Fiss Off Cream is going to be an “off-the-shelf” prescription-only cream containing:

  • Diltiazem which, based on the existing scientific literature, has the lowest risk of side effects compared to the alternatives GTN and nifedipine, but equal effectiveness.
  • Amethocaine – a smooth muscle relaxing local anaesthetic that both helps with the pain of fissures, but also (we think) will cause further sphincter relaxation, and improve healing.

Fiss Off Injectors will be a needleless botox injector using the principle of jet injection that will allow the botox treatment of fissures without needles or anaesthesia. We envisage that it will allow botox treatment of fissures in the consulting rooms of your doctor, thereby avoiding a hospital admission, and the costs associated with that treatment.