Anal fistula
An anal fistula is a small tunnel that develops between the end of the bowel and the skin near the anus (where poo leaves the body).
They are usually the result of an infection near the anus causing 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 won't usually get better on their own. Surgery is recommended in most cases.
Symptoms of an anal fistula include reddened skin around the anus, pain when the patient sits, moves, has a bowel movement or coughs, pus or bloody discharge during defecation, etc.
In general, an anal fistula develops following an anal abscess. This occurs when an abscess is not medicated in time, or when the drainage was not thorough enough.
An anal fistula can be described as a narrow tunnel with its internal opening in the anal canal and its external opening in the skin near the anus. Fistulaes are usually infections near the anus caused by the accumulation of pus.
An anal fistula is a condition which is almost always resolved by a surgeon. It is only when the fistula involves a single channel that its treatment is simple.