Most anal fistulae are thought to arise as a result of the infection of anal glands. This infection frequently presents as an anorectal abscess which requires drainage of the abscess under a general anaesthetic. Abscess and fistula should be considered as the acute and chronic phase of the same anorectal infection.The abscess represents the acute inflammatory event, whereas the fistula is representative of the chronic process. At the time of drainage of the anorectal abscess, the underlying fistulas frequently go undetected. As a result, patients present with a fistula in ano several months later.