A fistula-in–ano is an epithelial-lined tract connecting the anal canal to the perianal skin. Anal fistulas can have many causes but are most commonly the result of an anorectal
An anal fistula is a chronic abnormal communication between the anal canal and the perianal skin, often caused by anal abscesses
An anal fistula is a small channel that develops between the anus and the skin, often after an abscess
