1, what is an anal fistula, what are the symptoms of an anal fistula? Anal fistula means anorectal fistula. It is the aftermath of a perianal abscess that has broken down. The actual fact is that you can find a lot of people who are not able to get a lot of money from the internet. An anal fistula, on the other hand, has a tube that connects to the internal rectal sore and the external anal sore, with the internal rectal sore called the internal sore and the external sore called the external sore. The main symptoms of anal fistula are pus, anal itching and pain. The amount of pus flow is related to the inflammatory condition. In the acute inflammatory stage, there is a lot of pus and often a foul odor, and due to the curved and branching fistula, there is often pus accumulation. In the chronic inflammatory period, the pus flow is less, sometimes intermittent, and the pus is thin or in the form of rice slop secretions. Itching of the anus is caused by the discharge from the external fistula opening that irritates the local skin of the anus. Pain is caused by poor drainage, blockage of the canal by secretions, or recurrent inflammation. The pain can be distension or burning pain in the anus, but if there is no pus accumulation and blockage, there is usually no pain. The inflammatory phase of anal fistula may also be accompanied by systemic symptoms, such as chills and fever, and increased peripheral blood count. If the fistula is complicated by prolonged suppuration, it can also be accompanied by anemia, weight loss, and loss of appetite. 2. How is an anal fistula formed? A fistula is a fistula that connects to the anal canal or rectal cavity, and is a sequel to a perianorectal abscess. One end of the fistula is connected to the foci of infection in the anal sinus and anal glands in the anal canal, called the internal port, while the other end is connected to the skin around the anus, called the external port. The folk named it “anal fistula” because its main symptom is the constant outward flow of pus and pus and blood from the sores on the skin around the anus, just like a broken house that often leaks water. A serious anal fistula can be seen as a fecal outflow, so people call it “rat stealing feces”. A fistula is a tube with two fistula openings in the body and outside the body, which can leak secretions and pus outside the body. A sinus is characterized by a sinus floor and only one sinus tract that opens outward to leak secretions and pus and blood. There is a clinical distinction between a fistula and a sinus tract, and the two should not be confused. The formation of an anal fistula is the inevitable result of the development of a perianorectal abscess, and the formation of an anal fistula is roughly a four-stage process. The first stage is the infection of the anal fossa and flap, which is limited to local inflammation, and if not treated in time, the inflammation can spread around the anus. In the second stage, the inflammation starts in the localized anal fossa and flap and gradually spreads to form perianorectal inflammation. If the inflammation is not controlled, it may invade into the tissue interstices with low resistance to disease. In the third stage, as the resistance of the perianorectal tissue gap decreases, it becomes a place for germs to invade, spread, accumulate and multiply, making the tissues here susceptible to infection and inflammation. If anorectal abscess can be handled properly in the early stage, it can often be dissipated and cured without leaving sequelae; if the early treatment time is delayed or improperly handled, the tissue necrosis and pus can spread along its local gap, which will aggravate and complicate the condition. The fourth stage, the perianorectal abscess broke down by itself or after the incision and drainage of the change of treatment, although the pus cavity gradually reduced, but the ulcerated sores do not close the mouth for a long time, the cavity wall has formed a hard pipe wall of connective tissue hyperplasia, the gap left in the middle, which is the fistula, pus often flowed out from the fistula, repeated infection, repeated episodes, after a long time can not heal itself, and become a fistula.