Treatment of choice for low fistula in ano is -

Ans. is 'a' i.e. Fistulotomy * A fistula in ano is a track, lined by granulation tissue, that connects deeply in the anal canal or rectum and superficially on the skin around the anus.* It usually results from an anorectal abscess (cryptoglandular abscess)* Other causes are:# Crohn's ds., malignancy, radiation, tuberculosis, actinomycosis, chalamydia inf* It is divided into 2 types - high & low, according to whether their internal openings is below or above the anorectal ring.* The importance of deciding whether a fistula is a low or a high type is that a low level can be treated by fistulotomy (opening the tract) without causing damage to the sphincter.* High level fistulas can be treated only by 'staged' operation as there is risk of incontinence.