What is an anal fistula? An anorectal fistula is called an anal fistula, commonly known as a fistula, or in Chinese medicine, a leaky anus or leaky sore, because it has fluid leaking outward from the anus. A fistula is a tube formed when the soft tissue around the anus or rectum becomes infected with pus and breaks outward or after a perianal abscess is artificially cut open. The fistula starts as one and can have multiple ducts as the disease progresses. It is a difficult disease to treat in anorectology. How does an anal fistula form? (1) Infection of the anal sinuses and glands: Initially localized inflammation, which continues to develop and spreads around the anus. (2) Peri-anorectal inflammation stage: as the inflammation is not effectively controlled, it develops into the tissue interstices around the anorectum. (3) Peri-anorectal abscess stage: inflammation of the perianorectal tissue space leads to purulence, with four major features of localized redness, swelling and pain. (4) Formation of fistula stage: After the perianorectal abscess is collapsed or surgically incised and drained, the granulation tissue proliferates, the pus cavity gradually shrinks, and finally a hard-walled connective tissue tube is formed, leaving a gap in the middle, which is the fistula. What are the symptoms of anal fistula? 1:Local symptoms: pus or pus and blood flowing from the anal area, pain, itching, and poor defecation. 2:Systemic symptoms: general anal fistulae do not have systemic symptoms, but complicated anal fistulae and tuberculous anal fistulae are often accompanied by physical wasting, anemia, loss of appetite, constipation and difficulty in defecation. What are the treatments for anal fistula? At present, there are many ways to treat anal fistula, but in general, there are two kinds of conservative therapy and surgical therapy. Conservative therapy is the use of Chinese and Western medicine for internal or external use; surgical therapy is also divided into hanging wire therapy, incision method, incision hanging wire method, etc. Conservative therapy can only relieve the symptoms, but not achieve the purpose of the root cause, mostly for the old and frail or for various reasons temporarily should not be operated; surgical therapy can achieve the purpose of complete eradication of fistula. At present, the most advanced surgical methods are the “small incision and less damage” approach for low-level complex fistulas and the “non-wire therapy and preservation of the sphincter” approach for high-level complex fistulas. The basic principles of these two approaches are (1) to fully preserve the anal sphincter and (2) to reduce the damage to the incision under the condition of unobstructed drainage and to ensure the recovery time and flat appearance.