Anal fistula, also known as anorectal fistula, is an abnormal channel formed between the anal canal or rectum and the adjacent tissues around the anus for pathological reasons, mostly secondary to perianal and perirectal abscesses. It is characterized by recurrent perianal pus flow, pain and itching. It is called “anal leakage” in Chinese medicine.
I. Diagnosis
1.Symptoms
(1) History of perianal and perirectal abscess.
(2) Typical symptoms such as pus or pus and blood flowing from the anal area, anal swelling and pain, and itching of the perianal skin.
2.Signs
There is one or more fistula openings next to the anus that connect with the anal canal. There is an external opening around the anus that connects to the fistula tract, or there is an internal opening in the rectum that goes straight to the fistula tract, or the external opening around the anus connects to the internal opening in the rectum through a tunnel, and the skin around the external opening is visible as erythema and papules.
3.Anal fistula classification
(1) Classification by pathogen
(1) Purulent anal fistula: caused by bacterial infections such as Escherichia coli, Aspergillus, Pseudomonas aeruginosa and Staphylococcus.
(2) Tuberculous anal fistula: caused by tuberculosis bacteria.
(2) Classification according to the degree of lesion
①Simple anal fistula
Low simple anal fistula: only one canal and located below the rectal ring of the anal canal.
High simple anal fistula: only one canal, crossing the rectal ring or located on it.
②Complex fistula
Low complex fistula: with more than 2 ducts, located below the anorectal ring, and with more than 2 external or internal ports.
High complex fistula: more than 2 tubes, located above the rectal ring of the anal canal, with more than 2 external or internal ports.
Horseshoe-shaped anal fistula: the fistula is circumferential, with the external orifice on both sides of the anal part and the internal orifice mostly at 6 or 12 o’clock of the truncus position.
4.Common complications
The fistula is complicated by infection and perianal abscess, etc.
II. Treatment
General treatment principles.
Anal fistula has been clearly diagnosed, and the treatment is mainly surgical.