What causes an anal fistula?

An anal fistula is a common anorectal disease, primarily caused by infection of the anal glands or inadequate and delayed treatment of perianal abscesses. The formation of anal fistulas includes, but is not limited to, the following factors:

1. Perianal abscess: This is the most common cause. When a perianal abscess ruptures spontaneously or is incised and drained improperly, it can easily lead to the formation of an anal fistula.

2. Rectal or anal injury: Trauma or procedures such as anoscopy may cause injury to the anal canal or rectum. Bacterial invasion of the wound can lead to infection and subsequently an anal fistula.

3. Infection: Long-standing infections, such as recurrent anal fissures, may result in subcutaneous fistulas that can progress into anal fistulas. Additionally, specific infections such as tuberculosis, ulcerative colitis, and Crohn's disease may also cause anal fistulas.

4. Unhealthy lifestyle habits: Excessive consumption of spicy foods, irregular作息 (作息 should be translated as "lifestyle作息" or "作息" could be omitted depending on context), and prolonged sitting on the toilet are不良 habits (unhealthy habits) that may trigger perianal abscesses, leading to anal fistulas.

5. Anal fissures: Long-standing anal fissures may also lead to the development of anal fistulas.

6. Other diseases: Smoking, diabetes, obesity, chronic constipation, or diarrhea may indirectly increase the risk of developing anal fistulas.

If the above symptoms occur, timely medical attention is necessary to prevent worsening of the condition.