An anal fistula is an abnormal tunnel-like connection that forms between the inside of the anal canal or rectum and the skin around the anus. It typically develops as a result of an infection in an anal gland, leading to the formation of an abscess. When the abscess bursts, it may create a passageway or fistula. Here’s more information on anal fistulas:

Causes:

1. Anal Abscess: Most anal fistulas originate from an untreated anal abscess.
2. Crohn’s Disease: Inflammatory bowel diseases, such as Crohn’s disease, can increase the risk of fistula formation.
3. Infection: Infections in the anal glands or surrounding tissues can lead to the development of a fistula.
4. Trauma or Injury: Injury to the anal area, such as during childbirth or surgery, can contribute to the formation of a fistula.