What is Fistula-in-ano or anal fistula?
By definition a Fistula is a tunnel open at both ends.
Fistula-in-ano is such a tunnel which has one opening inside the anal canal and the other opening outside on the skin around the anus.
What causes a Fistula-in-ano?
Please read and try to understand.
Our inner wall of intestine is coated with slimy mucus to keep it free from friction due to the passing stools. Such mucus producing glands in the wall of the anal canal get infected by the stools and bacteria (which are present in huge numbers in stools) grow within the gland & produce pus by destroying the gland. Pus being liquid, it will find its way out and thus bursts open in the skin around the anus. Thus the inner opening is the mouth of the infected anal gland whereas the outer opening is the site on the skin where the abscess has ruptured thereby creating a communicating tunnel.
