Anal Fissure

What is an anal fissure?

An anal fissure is a small tear of the skin of the anus. Although the tear is small, it can be very painful because the anus is very sensitive. The pain tends to be worse when you pass faeces (sometimes called stools or motions) and for an hour or so after passing faeces. Often an anal fissure will bleed a little. You may notice blood after you pass faeces. The blood is usually bright red, stains the toilet tissue, but soon stops.

Anal fissures are common in both adults and children. They are not usually serious, but they are sore and can be distressing, particularly for children.

Common causes
Most anal fissures are thought to be due to passing large or hard faeces when you are constipated. The rim of the anus may stretch and tear slightly. Spasm (tightening) of the muscle around the anus (the sphincter) may play a part in causing the tear, or in slowing down the healing process. (If the muscle around the anus is tight, the blood supply to the anus is reduced. This may affect how well the tear heals.)

In about 1 in 10 cases, the fissure occurs during childbirth. Sometimes an anal fissure occurs if you have bad diarrhoea.

Anal fissures and other conditions
In a minority of cases, a fissure occurs as part of another condition. For example, as a complication of Crohn's disease or an anal herpes infection. In these cases you will have other symptoms and problems as well. These type of fissures are not dealt with further in this leaflet.

In most cases the fissure will heal within a week or so, just like any other small cut or tear to the skin. Treatment aims to ease the pain and keep the faeces soft whilst the fissure heals.

• Warm baths are soothing, and may help the anus to relax which may ease the pain.
• A cream or ointment that contains an anaesthetic may help to ease the pain. You should use this only for short periods at a time (5-7 days). If you use it for longer, the anaesthetic may irritate or sensitise the skin around the anus. You can get one on prescription. You can also buy some of these products at pharmacies without a prescription.
• A cream or ointment that contains a steroid may be prescribed by a doctor if there is a lot of inflammation around the fissure. Steroids reduce inflammation, and may help to reduce any swelling around a fissure. This may help to any ease 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 irritate.
• Painkillers such as paracetamol may help to ease the pain (but avoid codeine - see below).

• Eat plenty of fibre by eating plenty of 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, but some is passed out in the gut and softens the faeces. Most sorts of drink will do, but alcoholic drinks can be dehydrating and may not be so good.
• Fibre supplements. If a high fibre diet is not helping, you can take bran, or other fibre supplements ('bulking agents') such as ispaghula, methylcellulose, or sterculia. You can buy these at pharmacies or get them on prescription. Methylcellulose also helps to soften faeces directly which makes them easier to pass.
• Toileting. Don't ignore the feeling of needing the toilet to pass faeces. Some people suppress this feeling and put off going to the toilet until later. This may result in bigger and harder faeces 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.

There are separate leaflets called 'Constipation in Adults', 'Constipation in Children' and 'Fibre in the Diet' that provide more details about fibre and constipation.

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 faeces. This may lead to a vicious circle as then even larger and harder faeces form, which causes 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 faeces are soft and loose whilst the fissure heals.

An anal fissure will heal within 1-2 weeks in most cases, but takes longer to heal in some cases. A fissure lasting more than six weeks is called a chronic (persistent) anal fissure. Treatment with an ointment containing glyceryl trinitrate (GTN) may be advised if you have a chronic anal fissure. This often works, but some people require a minor surgical operation to cure a chronic anal fissure. (A separate leaflet called 'Chronic Anal Fissure' gives details.)

If you have had one anal fissure, after it has healed you have a higher than average chance of having another one at some time in the future. The best way to avoid a further fissure is not to become constipated by using the measures described above. That is, a high fibre diet, fluid, etc. Leaflets that list foods high in fibre are commonly available. Ask your practice nurse for one if you cannot obtain one.

© EMIS and PIP 2005   Updated: November 2005   PRODIGY Validated