13 March 2019 This may be a single connection between the two openings, or there may also be secondary connections. Secondary connections can be more or less complex , originating from the same opening in the anal canal and with multiple secondary openings. The incidence of anal fistulas is estimated at around 9 cases in 100,000, and is higher in men than in women . As a rule, it is more common when people are in their 40s. In children , anal fistulas are usually congenital and are more commonly seen in boys than in girls. Are there any causes for the development of anal fistula? In most cases, there is no specific cause for anal fistula. They are often the result of obstruction of the channels that drain the glands in the wall of the anal canal, near the anal sphincters. This obstruction, which prevents the drainage of secretions from glands in the anal canal, causes an inflammatory process and leads to the formation of a fistula tract. Usually, this tract goes towards the body surface, with an opening at the skin through which the contents will be drained. If this opening heals, a new accumulation of pus collects in the fistula tract and the process is repeated. Anal fistula may also develop as a result of: Perirectal or anal trauma; Anal fissure; Crohn’ s Disease; Diverticulitis; Malignant anorectal diseases; Tuberculosis; Other infectious diseases. What are the symptoms of anal fistula? The most common symptoms of anal fistula include: Recurrent abscesses on the skin, interspersed with purulent and/or bloody discharge; Anal itching; Swelling in the local area; Pain in the local area; Systemic symptoms where there is infection. How is anal fistula diagnosed? Anal fistula is diagnosed on the basis of: Clinical history; Existing symptoms; Examination of the patient. Examination of the perianal region may reveal a hardened, reddish and painful area. In addition, it is usually possible to observe an abscess or the opening of the fistula , which may have pus running through it. The site of the opening of the fistula can often gives some idea of its trajectory. Sometimes it can even be identified by palpation. In some cases, further examinations may be necessary , including: Investigation with a fistula probe - this is inserted through the external opening and will make it possible to determine the length and shape of the fistula tract; An anoscopy - will make it possible to identify the internal opening of the fistula; Local injection of a specific dye -will make it possible to identify the length and shape of the fistula tract; A fistulography - the injection of a contrast agent into the fistula, followed by an X-ray examination; Endoanal ultrasound; Magnetic resonance. In cases where it is necessary to rule out the possibility of other underlying diseases, flexible sigmoidoscopy or colonoscopy may also be necessary. How are anal fistulas treated? The treatment of anal fistula includes medical treatment of any infection that may be present and surgical correction of the fistula. Fistulas do not heal spontaneously, so surgical treatment is essential. The type of surgical approach to be taken depends on the specific features of the case, including the location and complexity of the fistula , and its degree of interference with the anal sphincter. Surgical treatment may involve: Excision of the fistula (fistulectomy) and suturing of the site; Cutting the tissues along the fistula tract to the opening (fistulotomy) to expose the connection between the internal and external openings, allowing them to heal in the direction of the surface; Drainage of the fistula tract using a surgical thread - known as a seton - in cases where the removal or exposure of the fistula tract would lead to the destruction of the anal sphincter (fistula tracts that are higher up); This thread keeps the tract drained and open, which prevents abscesses from forming; Meanwhile, the thread slowly divides the tissues and helps them to heal at the same time, which makes it possible to avoid incontinence; Closure of the internal opening of the fistula and filling of the tract, after it has been cleaned, with a specific biodegradable product that will help to heal it from the inside. This approach does not require any of the tissue to be cut. Regardless of the surgical approach adopted, the objective is to remove the fistula without interfering with the functionality of the anal sphincter , that is, by maintaining its capacity to control the emission of gas and stools. Anal fissure falls into the field of coloproctology, which is part of the activity carried out by gastroenterologists and general surgeons . This article was written with the support of general surgeons from the Hospital da Luz network. Our Health Guide contents have an information purpose, are intended for the general public and may not be up to date. They do not replace the information, opinion and individual advice of a doctor or other healthcare professional in their areas of expertise.
