What is an anal abscess?
An anorectal abscess is a perianal infection mostly following an anal fissure. The pain tends to be worse when you pass faeces (sometimes called stools or motions) and for an hour or so after passing faeces.
What causes an anal abscess?
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.
What is the treatment for an anal abscess?
Treatment aims to remove the abscess through incision and drainage
Easing pain and Discomfort
• 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).
AVOIDING CONSTIPATION AND KEEPING FAECES SOFT
• 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.
What are the treatments for chronic (non-healing) anal fissure?