Experts from the Nanjing Armed Police Hospital's Anorectal Center introduced that anorectal fistulas mainly invade the anal canal and rarely involve the rectum, so they are commonly referred to as anal fistulas. These are granulomatous channels connected to the perineal skin with internal openings often located near the dentate line and external openings on the perianal skin. The entire fistula wall is composed of thickened fibrous tissue covered by a layer of granulation tissue inside, which does not heal for a long time. The incidence rate ranks second only to hemorrhoids and is more common in young and middle-aged men. Anal itching treatment [http://www.jsgcw.com/gangmensaoyang/] may be related to the vigorous secretion of sebaceous glands, one of the sex hormone target organs in men.
### Causes and Classification
Most anal fistulas form after the rupture or incision and drainage of perianal abscesses. As the abscess gradually shrinks, intestinal contents continue to enter the abscess cavity. During the healing and shrinking process, tortuous cavities often form. Poor drainage makes it difficult for the wound to heal, and over time, much scar tissue forms around the cavity, leading to chronic infection of the channel. This channel runs near the internal and external sphincters. The external opening grows relatively fast, often resulting in false healing, causing repeated episodes. Infections in the channel are mostly purulent, but some can be tuberculous.
Based on the position, depth, height, and number of the fistula openings and channels, classifications include:
1. **External Fistula and Internal Fistula**: External fistulas have at least two openings - one on the perianal skin (usually 2-3 cm from the anus) called the external opening, and another inside the bowel cavity, usually at the dentate line in the anal sinus, called the internal opening. Some internal openings are above the mid-dentate line on the rectal wall. Internal fistulas have similar internal openings but no wounds; clinically, 90% are external fistulas.
2. **Low Fistula and High Fistula**: If the fistula channel is below the anorectal ring plane, it is considered a low fistula; if it is above this plane, it is considered a high fistula. The latter is relevant for choosing the treatment method.
### Types of Anal Fistulas
There are more than twenty classification methods for anal fistulas worldwide. According to the Hengshui Conference in China (1975), the unified standard classification of anal fistulas is based on the deep part of the external sphincter muscle. If the fistula passes through this line, it is classified as high; if it is below this line, it is classified as low. A simple anal fistula has only one internal opening, one fistula channel, and one external opening. A complex anal fistula has two or more internal openings, fistula channels, and external openings. This classification method is now widely used domestically.
1. **Low Simple Anal Fistula**: Only one fistula channel passing through the deep part of the external sphincter muscle, with the internal opening near the anal sinus.
2. **Low Complex Anal Fistula**: Fistula channels pass through the deep part of the external sphincter muscle, with two or more external openings and channels, and one or several internal openings near the anal sinus.
3. **High Simple Anal Fistula**: Only one fistula channel passing through the deep part of the external sphincter muscle, with the internal opening near the anal sinus.
4. **High Complex Anal Fistula**: Two or more external openings with branched channels.
5. **Simple Anal Fistula and Complex Anal Fistula**: The former has only one fistula channel, while the latter can have multiple openings and channels.
Many anal fistula patients are unwilling to undergo surgery. Some so-called easy-to-treat, inexpensive family secret formulas have caught the attention of some anal fistula patients. Experts from the Nanjing Armed Police Hospital's Anorectal Center remind patients not to fall for scams. In medical classification, anal fistulas belong to surgical diseases, and only surgical treatment can cure them.
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[**Nanjing Armed Police Hospital Anorectal Center**] [http://www.jsgcw.com]
[**Nanjing Armed Police Hospital Anorectal Center**] [http://www.njgcyy.net]
[**Nanjing Armed Police Hospital Anorectal Center**] [http://www.jswjyy.com]
[**Nanjing Armed Police Hospital Anorectal Center**] [http://www.wjgc.net]
Consultation Phone: 025-85500079 Consultation QQ: 997287111
Hospital Address: No. 256, Heyan Road, Nanjing (100 meters to the right of the North Gate of Hongshan Zoo)
Transportation Route: Get off at Hongshan Zoo Station on Subway Line 1; take bus routes 30, 8, 64, 54, 72, 77, Yuge Line, Nanzhou Line and get off at Dongjingting Station;
[**Yangzhou Armed Police Hospital Anorectal Center**] [http://www.yzwjyy.com]
Consultation Phone: 0514-87218120 Consultation QQ: 997287111
Hospital Address: No. 8 Jiangdu South Road, Yangzhou, Jiangsu Province
Transportation Route: Take buses 4, 19, 25, 26, 26 evening, 66, 66 evening, 101, 102, 201, 208, 209 in Yangzhou city and get off at the Armed Police Hospital station;
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