| Anal fistula | |
|---|---|
| Other names | Anal fistulae, fistula-in-ano, anorectal fistula |
![This is a modified version of the original by Armin Kübelbeck [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons, https://commons.wikimedia.org/wiki/File%3APiles_diffdiag_01.svg Specifically, it was made fistula-specific by removing abscess labels.](/wiki/File:Fistula_diag_01.svg) | |
| Different types of anal fistula | |
| Specialty | General surgery |
| Symptoms | Pain, drainage of pus.[1] |
| Usual onset | 20s to 40s[2] |
| Duration | Long standing[3] |
| Types | Simple, complex[2] |
| Causes | Anal abscess[4] |
| Risk factors | Obesity, diabetes, smoking, high blood lipids, lack of exercise[2] |
| Diagnostic method | Examination under anesthesia, medical imaging[2] |
| Differential diagnosis | Anal carcinoma, anal fissure, hemorrhoids, perianal abscess, diverticulitis, hidradenitis suppurativa, pilonidal cyst[2][5] |
| Treatment | Surgery[2] |
| Frequency | 12 per 100,000 (males)[2] 6 per 100,000 (females)[2] |
An anal fistula is a abnormal communication between the anal canal and usually the skin around the anus that is long standing in nature.[1][3] Symptoms may include rectal pain and drainage of pus.[1] Complications may include fecal incontinence, anal stenosis, and recurrence of the fistula.[2]
The most common cause is a prior anal abscess which does not heal properly.[4] Risk factors include Crohn disease, radiation therapy, obesity, diabetes, smoking, high blood lipids, and a lack of exercise.[2] They generally start from an anal gland, which are located between the internal and external anal sphincter and drain into the anal canal.[5] If there is a single tract, less than 30% involvement of the external sphincter, and no underlying cause it is classified as simple, otherwise it is classified as complex.[2] Diagnosis may require examination under anesthesia or medical imaging.[2]
Treatment is generally via surgery using one of a number of techniques.[2] Antibiotics are typically not needed.[2] Though, those related to Crohn disease may be, at least initially, treated with medications.[2] About 12 in 100,000 males and 6 per 100,000 females are affected.[2] Onset is usually between the ages of 20 and 40.[2] It occurs in 30% to 50% of individuals with anal abscess.[4]
References
edit- ^ a b c "Anorectal Fistula". Merck Manual Consumer Version. Archived from the original on 2016-07-10. Retrieved 2016-06-27.
- ^ a b c d e f g h i j k l m n o p q Carr, S; Velasco, AL (January 2020). "Fistula In Ano". StatPearls. PMID 32491449.
- ^ a b Taylor, Robert B. (2002). Manual of Family Practice. Lippincott Williams & Wilkins. p. 337. ISBN 978-0-7817-2652-8. Archived from the original on 2021-08-27. Retrieved 2020-10-30.
- ^ a b c Madoff, Robert D.; Melton-Meax, Genevieve B. (2020). "136. Diseases of the rectum and anus: anal fistula". In Goldman, Lee; Schafer, Andrew I. (eds.). Goldman-Cecil Medicine. Vol. 1 (26th ed.). Philadelphia: Elsevier. p. 935. ISBN 978-0-323-55087-1. Archived from the original on 2023-03-15. Retrieved 2023-03-15.
- ^ a b Jimenez, M; Mandava, N (January 2020). "Anorectal Fistula". StatPearls. PMID 32809492.