An anal fistula is a medical condition in which a tunnel-like channel develops between the inside of the anus and the skin around the anus. The condition usually develops after an anal abscess has been drained. Anal fistulas can be classified into four different types based on their location and extent. Dr. Samrat Jankar at Kaizen Gastro Care, Wakad, Pune treats all types of Fistula.
The types of anal fistulas are:
1. Intersphincteric Fistula:
An intersphincteric fistula is the most common type of anal fistula.It stays within the internal anal sphincter, which is a ring-shaped muscle that surrounds the anus. This type of fistula usually causes mild symptoms, such as pain and discharge from the anal opening.
2. Transsphincteric Fistula:
A transsphincteric fistula is a tunnel-like channel that develops through the internal and external anal sphincter muscles. It extends from the inside of the anus to the skin around the anus. A high transsphincteric fistula can also cause fecal incontinence, which is the inability to control bowel movements.
3. Suprasphincteric Fistula:
A suprasphincteric fistula is a tunnel-like channel that develops above the internal anal sphincter. It extends from the inside of the anus to the skin around the anus, passing through the levator ani muscle. This type of fistula usually causes severe symptoms, such as intense pain, swelling, and discharge. It can also cause fecal incontinence, which is the inability to control bowel movements.
4. Extrasphincteric Fistula:
An extrasphincteric fistula is a tunnel-like channel that develops outside the external anal sphincter. It extends from the inside of the anus to the skin around the anus, passing through the levator ani muscle. This type of fistula is the least common but the most complex. It can also cause fecal incontinence, which is the inability to control bowel movements.
5. Simple/complex fistula:
‘Simple’ Fistulas: Simple fistulas are typically intersphincteric or low transsphincteric fistulas involving less than 30% of the external sphincter. These fistulas have limited sphincter involvement, making them more amenable to treatment with sphincter-cutting procedures. Due to their less extensive nature, simple fistulas have a higher likelihood of successful healing with such procedures.
‘Complex’ Fistulas: Complex fistulas, on the other hand, have more extensive muscle involvement and may include anterior fistulas in female patients, recurrent fistulas, and those associated with preexisting fecal incontinence, inflammatory bowel disease, or radiation. Managing complex fistulas can be more challenging due to their complexity and associated risk factors. As a result, these fistulas are often treated with specialized and newer modalities that aim to preserve the sphincter function (sphincter-saving procedures) while effectively closing the fistula.
