An anal fistula is an irregular tunnel under the skin that connects the skin on the buttocks to the anal canal. As a result of an abscess or pus-filled infection, most anal fistulas form, beginning in the lining of the anus and penetrating into the skin. Antibiotics alone can not heal it if you have an anal fistula. Centre for Piles offers the best Ayurvedic Treatment For Fistula at an affordable charge.