Anal abscess

An anal abscess is a painful condition that occurs when a small gland inside the anus becomes infected. This leads to the formation of pus, creating a swollen, painful lump near the anus. The exact cause of anal abscesses is not always clear, but they are more common in people with conditions such as Crohn’s disease.

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In some cases, an anal abscess can burst on its own, releasing pus. However, many require medical treatment. If left untreated, around 50% of cases develop an anal fistula – a small tunnel between the anus and the skin.

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Symptoms of an anal abscess

If you have an anal abscess, you may experience:

• Severe pain – often constant and throbbing, worse when sitting or moving

• Swelling around the anus

• Tenderness when touching the affected area

• Redness and warmth around the lump

• Pus drainage if the abscess bursts

• Flu-like symptoms – fever, chills, and fatigue as a result of local infection

 

If you notice these symptoms, it’s important to seek medical attention promptly to prevent complications.

 

How is an anal abscess diagnosed?

When you are seen in clinic, the consultant will:

• Take a full medical history and discuss your symptoms

• Examine the area to assess the abscess

 

Usually, an abscess is readily apparent on examination. If the area is too uncomfortable to examine, then the consultant may recommend carrying out an examination under anaesthetic to confirm the diagnosis, where the abscess can be treated at the same time.

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• Sometimes an MRI scan or endoanal ultrasound scan will be recommended, particularly if the problem is longstanding or recurrent

• If you are over the age of 40 years and have had any bleeding or change in bowel habit, the consultant may recommend an endoscopic examination of the bowel either by flexible sigmoidoscopy or colonoscopy to ensure that it is otherwise healthy. Again, this can often be carried out alongside treating the abscess

 

Treatment for an anal abscess

The best way to treat an anal abscess is through a minor surgical procedure to drain the pus. This is usually done under general anaesthetic and involves:

• Making a small incision in the skin to release the pus

• Draining the abscess to reduce pain and swelling

• In some cases, a small drain may be placed to prevent pus from re-collecting

 

What to expect after surgery

• Most patients can go home within 24 hours

• Antibiotics may be prescribed, especially for those with diabetes or immune conditions

• You will need regular dressing changes to keep the area clean:

  • small abscesses – you may be able to do this yourself

  • larger abscesses – a nurse may assist with dressings

 

Keeping the area clean and dry is essential for healing. Read our aftercare guide for anal surgery for hygiene tips.

 

How long does healing take?

Healing usually takes 4 to 6 weeks. However, if an anal fistula has developed, additional treatment may be needed.