what is fistula disease

A fistula is an abnormal connection between two body parts, such as an organ or blood vessel and another structure. Fistulas are usually the result of an injury, surgery, infection, or inflammation. They may occur in many parts of the body, including the anus. An anal fistula is a small tunnel that develops between the end of the bowel and the skin near the anus. It is usually caused by an infection near the anus, which results in a collection of pus (abscess) in the nearby tissue. When the pus drains away, it can leave a small channel behind. Anal fistulas can cause unpleasant symptoms, such as discomfort and skin irritation, and will not usually get better on their own. Surgery is recommended in most cases