Causes and Risk Factors of Anal Fistula
Anal fistulas are usually the result of a previous anal abscess. The anal glands — tiny openings inside the rectum — can become blocked or infected, forming an abscess. When that abscess drains (naturally or surgically), a fistula can remain. Read more about causes and risk factors of anal fistula below.
Most Common Cause:
- Anal abscess – Occurs when a blocked anal gland becomes infected and forms a pocket of pus.
Other Causes and Risk Factors:
- Inflammatory Bowel Disease (IBD)
- Especially Crohn’s disease, where chronic inflammation increases the risk of fistula formation
- Tuberculosis
- Still present in parts of South Africa; can cause anal or perianal fistulas
- Radiation therapy
- Pelvic or rectal radiation may damage tissues and lead to fistulas
- Surgery or trauma
- Prior rectal surgery or injury can sometimes result in fistula formation
- Sexually transmitted infections (STIs)
- Particularly those involving ulcers or abscesses
- HIV/AIDS
- Increases the risk of infections and complications
Fistulas are not caused by poor hygiene or diet, though chronic constipation or diarrhoea may irritate the area and complicate healing.
Some people may develop multiple or branching fistulas, particularly if the underlying condition (like Crohn’s disease) remains untreated.
Let’s now explore how anal fistulas are diagnosed by healthcare providers.
👉 [Next: Diagnosis of Anal Fistula]
