An infected, pus-filled cavity in the anal or rectal area
An anal abscess is a pus-filled cavity that develops when bacteria enter a mucus-secreting gland in the anus or rectum and multiply. The abscess may be deep within the rectum or close to the anus.
Inflammatory disorders of the colon, such as Crohn’s disease, can be associated with anal abscesses. Anal sex also increases the risk.
You should consult a doctor if you have swelling or redness in the anal area or have a throbbing pain that worsens with defecation. If the infection spreads from the anal area, you may also have a fever and feel generally unwell.
An anal abscess is usually diagnosed by a physical examination. Treatment involves draining the abscess through an incision under local anaesthesia. Drainage of deep or large abscesses may need a general anaesthetic. You may be given oral antibiotics and advised to soak the affected area in warm water three or four times a day. An abscess may take several weeks to heal.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.