FISTULA- IN-ANO Aetiology

FISTULA- IN-ANO Aetiology

A fistula- in - ano , or anal fistula, is a chronic abnormal commu nication extending from the anorectal lumen (the internal opening) to an external opening on the skin of the perineum or buttock (or rarely , in women, to the vagina). T he majority are idiopathic or cryptoglandular and are lined by granulation tissue. Anal fistulae may be found in association with Crohn’s disease, tuberculosis, lymphogranuloma venereum, actinomy cosis, rectal duplication, foreign body and malignancy (which may also very rarely arise within a longstanding fistula).