Anal Fissure, Fistula and Abscess

Anal Abscess and Fistula

An abscess is a localized pocket of pus caused by infection from bacteria. It can occur in any part of the body. When bacteria seep into the underlying tissues in the anal canal, an abscess may develop. Certain conditions, such as Crohn’s disease (chronic inflammatory bowel disease), can increase the risk of abscess in and around the anal canal. Patients with conditions that reduce the body’s immunity, such as cancer or AIDS, are also more likely to develop anal abscesses.

An abscess causes tenderness, swelling, and pain. These symptoms clear when the abscess is drained. The patient may have fever, chills, and general weakness or fatigue.

A fistula is a tiny channel or tract that develops in the presence of inflammation and infection. It may or may not be associated with an abscess, but like abscesses, certain illnesses such as Crohn’s disease can cause fistulas to develop. The channel usually runs from the rectum to an opening in the skin around the anus. However, sometimes the fistula opening develops elsewhere. For example, in women with Crohn’s disease or obstetric injuries, the fistula could open into the vagina or bladder.

Since fistulas are infected channels, there is usually some drainage. Often, a draining fistula is not painful, but it can irritate the skin. An abscess and fistula often occur together. If the opening of the fistula seals over before the fistula is cured, an abscess may develop behind it.