Perianal fistula can affect approximately 10 out of every 100,000 inhabitants. It has been proven that it occurs in the average age of life and that the incidence in men is double that in women.
The perianal fistula is an abnormal path or communication that is established between the interior of the anal canal and the skin surrounding the anus. Therefore, most fistulas have an internal orifice located at different heights of the anal canal, have a path, which can pass through the muscles or sphincters that govern the closure and opening of the anus and have an external hole in the skin through from which comes a purulent fluid and sometimes fecal content.
Pain and constant or intermittent suppuration are the fundamental symptoms of a patient who has a perianal fistula. When a perianal abscess appears, other symptoms such as fever and the presence of a warm lump and tension in the perianal region are added.
How it is produced
Most perianal fistulas have their origin in glands that are located in the anal canal and whose mission is to lubricate the mucosa that covers the canal. These glands have small exit channels, which communicate with each other until they find the easiest place to drain their mucous contents.
If such drainage is made difficult by increasing the viscosity, it can cause an obstruction of the glands, which will be dilated and progressively extended by adjacent areas. At any time a colonization of the glands by germs can occur, over-affecting them and giving rise to the appearance of an abscess or collection of pus .
Therefore, it is not surprising that most of the patients who consult for a fistula report having suffered a previous perianal abscess that either drained spontaneously, or as it happens most of the time, required an urgent surgical intervention to empty it. and clean it, which is known as "surgical debridement " .