Perianal Abscess/Fistula

What is it?

An abnormal connection between the anal canal and the skin surface adjacent to the anus. This track contains infected fluid (pus)
A painful abscess can occur if the fluid cannot escape. A fistula may develop if the discharge is persistent

What causes them?

Throughout the anal canal there are glands which produce mucus to lubricate the passage of stool
If one of these glands in the anal canal becomes blocked, the trapped mucus becomes infected. The infected fluid finds its way to the surface through the skin or back into the anal canal producing a fistula.


An abscess is an acutely painful swelling near the anus.
A perianal fistula is a persistent discharge of infected fluid. Once discharge occurs then the pain is relieved


Antibiotics are not effective. The abscess should be drained with immediate relief to the patient.
If there is a fistula present then the patient will need to be referred to an experienced colorectal surgeon for assessment and usually an operation.