What is anal fistula? What are the causes of morbidity?

Anal fistula refers to the rectum and anal canal linked to the skin around the anus infectious pipeline Also known as "anorectal fistula." I often located within its tooth line near the mouth of the perianal skin, mouth fistula years. Civil According to its main symptom is the skin around the anus from the repeatedly discharging to the outside world, like broken homes often leaks, we hear the ancestors of the disease known as fistula. Fistula is the body cavity and in vitro have two exchange pipeline, which can leak from in vitro to in vivo secretion and pus, serious anal fistula visible feces outflow, as sore a hole hidden the stolen rat feces from time to time harm people steal manure, so the image to the anal fistula called "steal rat feces." The disease can occur at any age, but 30 ~ 40-year-old middle-aged sick more easily, more men than women.
As already mentioned anal fistula is anorectal diseases around the aftermath of the abscess, anorectal around abscess caused anal fistula is the fundamental reason. After incision abscess rupture or not healing, and ultimately fistula formation, its main causes:
① anorectal incision around abscess rupture or more in the anus, pus population outflow from the outside, but in many primary anal sinus infection. Anal secondary sinus infection is the gateway, repeated infections, fistula formation.
② fistula Road in between through the anal sphincter, as always constantly sphincter contraction and relaxation, oppression fistula Road, the impact of pus excluded, easy storage septic infection and difficult to heal.
③ rectum with a certain degree of pressure, rectal infection such as fecal material, the gas can be constantly in the mouth from entering fistula Road, stimulate wall, secondary infection after discharge from the mouth, is also a fistula causes.
④ anorectal around abscess rupture, pus drained Vomica gradually narrowed, Rupture mouth and external incision also narrowed, a wall of connective tissue hyperplasia hard pipe wall and therefore can not natural closure.
⑤ fistula bending, or sinus, branch, not open drainage, pus retention, repeated infections, caused fistula difficult healing.
⑥ anal venous drainage impeded, local recurrent congestion, organizations malnutrition, affect healing.
⑦ Mycobacterium tuberculosis, Actinomyces infected by the formation of abscesses, Crohn's disease, and so difficult to self-healing and particularity of anal fistula formation.