The annual incidence of perianal abscess is estimated between 14 000 and 20 000 people in the UK, resulting in about 12 500 operations in the NHS each year.1 A recent Swedish cohort study estimated the incidence at 16.1 per 100 000.2 The true incidence may be higher, since many patients are treated with antibiotics in the community and some abscesses spontaneously regress or discharge.23 Patients usually present with an erythematous swelling near the anus and may be embarrassed or reluctant to seek treatment. They may present to a non-specialist in the first instance. This article provides information on the causes and different types of perianal abscess and an update on how they are best managed.