An anal fissure is a small tear of the skin around the back passage (anus). An anal fissure that lasts more than six weeks is called a chronic anal fissure.
It may not be an issue you make a habit of discussing with your friends, but lots of us get to learn about anal tears (fissures) the hard way. They're not usually serious but they are most definitely painful! For most people, the anal fissure gets better quite quickly but some form of treatment is often needed and anal fissures may keep coming back.
What are the symptoms of an anal fissure?
An anal tear (fissure) causes pain around the back passage (anus). The pain can be really bad and tends to be worse when you pass stools (faeces) and for an hour or so after passing stools. You may also get some bleeding when you pass stools - usually bright red, in the pan or on the toilet paper. Bleeding from the back passage should always be checked by a doctor. In most people, the fissure heals within 1-2 weeks or so but it can take much longer.
How are anal fissures diagnosed?
Your doctor will usually diagnose an anal tear (fissure) by your typical symptoms and by examining the skin around your back passage (anus). No other tests are usually needed but your doctor may arrange some other tests just to check your gut (bowel) and back passage are otherwise okay.
How common are anal fissures?
Anal tears (fissures) are common and probably affect about 1 in 350 people each year. They are more common in people aged between 15 and 40 years but can occur at any age, including in very young children. Women who are pregnant or have recently had a baby are at higher risk of anal fissures, while they are much less common in the elderly.
What are the causes of an anal fissure?
Anal fissures are most often caused by damage to the back passage (anus). Stretching and tearing of the rim of the anus can occur when a person passes particularly hard stools (faeces). In most people, this skin damage will heal quickly without any problems. However, some people seem to have a higher than normal tone (pressure) of the muscle around the anus (the anal sphincter). The muscle is 'tighter' than usual.
It is thought that this increased tone may reduce the blood supply to the anus and so slow down the skin healing process. This can cause an anal tear (fissure) to develop. Once a fissure has developed, pain when passing stools can increase the anal tone further. This makes the pain worse, which can then increase the muscle tone even more and further slow down the healing process.
Constipation can make an anal fissure more likely to develop. There's major variation in 'normal' frequency of bowel-opening between different people. For some, 2-3 times a day is standard and going three days without a bowel movement would be very unusual. For others, going more often than every 2-3 days would be equally odd. Constipation either happens if your stools become hard and it's harder and/or more painful to go, or you're going significantly less often than usual.
Lots of factors can cause constipation, but among the most common are not eating enough fibre (roughage) and not drinking enough fluids. If you're generally unwell, particularly with a feverish illness, you'll be losing more fluid than usual - due to sweating from your high temperature (fever) - and often eating less. Some medications - particularly strong painkillers - can also make you constipated. So can medical conditions such as an underactive thyroid gland.
Sometimes an anal fissure occurs if you have bad diarrhoea. Anal fissures are also more common during pregnancy and childbirth. An anal fissure occurs in about 1 in 10 women during childbirth.
In a small number of cases, a fissure occurs as part of another condition. For example, as a complication of Crohn's disease, ulcerative colitis or a sexually transmitted infection such as anal herpes infection. In these situations you will also have other symptoms and problems that are caused by the underlying condition. These types of fissures are not dealt with further in this leaflet.
What are the treatment options for an anal fissure?
For most people the tear (fissure) heals within a week or so, just like any other small cut or tear to the skin. Treatment aims to ease the pain and to keep the stools (faeces) soft whilst the fissure heals.
Easing pain and discomfort
- Warm baths are soothing and they may help the back passage (anus) to relax which may ease the pain.
- A cream or ointment that contains an anaesthetic such as lidocaine may help to ease the pain. You should only use this for short periods (up to 5-7 days). If you use it for longer, the anaesthetic may irritate or sensitise the skin around the anus. You can obtain one of these creams or ointments on prescription. You can also buy some of these products at pharmacies, without a prescription.The cream/ointment should be applied before going to the toilet.
- A cream or ointment that contains steroid medication may be prescribed by a doctor if there is a lot of swelling (inflammation) around the fissure. Steroids reduce inflammation and they may help to reduce any swelling around a fissure. This may help to ease any itch and pain. You should not use it for longer than one week at a time.
- Wash the anus carefully with water after you go to the toilet. Dry gently. Don't use soap whilst it is sore as it may cause irritation.
- Painkillers such as paracetamol or ibuprofen may help to ease the pain (but avoid codeine - see below).
Avoid constipation and keep the stools soft
- Eat plenty of fibre which is found in fruit, vegetables, cereals, wholemeal bread, etc.
- Have lots to drink. Adults should aim to drink at least two litres (10-12 cups) of fluid per day. You will pass much of the fluid as urine. However, some is passed out in the gut and softens the stools. Most sorts of drink will do; however, alcoholic drinks can lead to lack of fluid in the body (dehydration) and may not be so good.
- Fibre supplements and laxatives. If a high-fibre diet is not helping, you can take fibre supplements (bulking agents) such as ispaghula, methylcellulose, bran or sterculia. Methylcellulose also helps to soften stools directly, which makes them easier to pass. You can buy these at pharmacies or obtain them on prescription. A laxative such as lactulose or a macrogol laxative may sometimes be suggested.
- Toileting. Don't ignore the feeling of needing to pass stools. Some people suppress this feeling and put off going to the toilet until later. This may result in bigger and harder stools forming that are more difficult to pass later.
- Avoid painkillers that contain codeine, such as co-codamol, as they are a common cause of constipation. Paracetamol is preferable to ease the discomfort of a fissure.
Anal fissures in children
The above measures apply to children who have a fissure as much as to adults. In children, the pain often makes them hold on to their stools. This may lead to a vicious circle, as then even larger and harder stools form. These then cause more pain when they are finally passed. Therefore, in addition to the above measures, a short course of laxatives may be prescribed for children with an anal fissure. The aim is to make sure their stools are soft and loose whilst the fissure heals.
What if the anal fissure does not heal with the above measures?
An anal tear (fissure) will usually heal within 1-2 weeks in most people. However, it can take longer to heal in others.
Glyceryl trinitrate ointment
If you apply glyceryl trinitrate (GTN) ointment to the anus, it relaxes the muscle around the anus (the anal sphincter). It also increases the blood supply to the damaged skin by dilating the blood vessels in that area. This may allow the fissure to heal better. It may also ease the pain.
GTN ointment may help in some, but not all, cases. Research studies showed that, for people with a chronic anal fissure, about 6 in 10 fissures healed with GTN treatment. This compared to about 5 in 10 that healed with no treatment. So, the effect of GTN ointment is modest but may well be worth a try.
Some studies have shown that other medicines may also help to relax the anal sphincter muscle and increase the blood supply to the area, so helping healing of an anal fissure. For example, medicines called calcium-channel blockers, such as diltiazem. These medicines may sometimes be suggested for people unable to use GTN ointment.
An injection of botulinum toxin into the anal sphincter muscle has also been shown to relax the anal sphincter muscle and so help anal fissures to heal. This treatment may be suggested if other treatments have not been successful.
An operation is an option if the fissure fails to heal or comes back. The usual operation is to make a small cut in the muscle around the anus (internal sphincterotomy). This permanently reduces the tone (pressure) around the anus and allows the fissure to heal. This is a minor operation which is usually done as day case surgery (you will not usually have to stay overnight in the hospital). The success rate with surgery is very high. At least 9 in 10 cases are cured.
Further reading & references
- Anal Fissure; NICE CKS, July 2016 (UK access only)
- Brown CJ, Dubreuil D, Santoro L, et al; Lateral internal sphincterotomy is superior to topical nitroglycerin for healing chronic anal fissure and does not compromise long-term fecal continence: six-year follow-up of a multicenter, randomized, controlled trial. Dis Colon Rectum. 2007 Apr;50(4):442-8.
- Mentes BB, Tezcaner T, Yilmaz U, et al; Results of lateral internal sphincterotomy for chronic anal fissure with particular reference to quality of life. Dis Colon Rectum. 2006 Jul;49(7):1045-51.
- Nelson RL, Thomas K, Morgan J, et al; Non surgical therapy for anal fissure. Cochrane Database Syst Rev. 2012 Feb 15;2:CD003431. doi: 10.1002/14651858.CD003431.pub3.
- Yiannakopoulou E; Botulinum toxin and anal fissure: efficacy and safety systematic review. Int J Colorectal Dis. 2012 Jan;27(1):1-9. doi: 10.1007/s00384-011-1286-5. Epub 2011 Aug 6.
- Samim M, Twigt B, Stoker L, et al; Topical diltiazem cream versus botulinum toxin a for the treatment of chronic anal fissure: a double-blind randomized clinical trial. Ann Surg. 2012 Jan;255(1):18-22. doi: 10.1097/SLA.0b013e318225178a.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but makes no warranty as to its accuracy. Consult a doctor or other healthcare professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Colin Tidy
Prof Cathy Jackson