A fistula occurs when two body parts or blood vessels connect abnormally, often due to injury or surgery. Fistulas are relatively common and can develop in various areas of the body, such as between the throat and neck, cervix and vagina, or bowel and peritoneal cavity.
An anal fistula is a small channel that links an abscess (a cavity filled with pus) to the skin around the anus. The primary cause of an anal fistula is typically an infection in the anal glands. These glands produce a lubricating substance that protects the anus but can become blocked by debris, leading to an abscess. If untreated, this abscess may develop into a fistula. Inflammation can also contribute to fistula formation.
Symptoms of Anal Fistula
Anal fistulas can cause a range of symptoms, including:
- Pain around the anal area
- Swelling
- Frequent abscesses near the anus
- Redness and skin irritation
- Discharge of blood or pus (which may have a foul odor)
- Fatigue
- Fever and chills
Causes of Anal Fistula
Anal fistulas commonly develop after an untreated anal abscess. However, other factors that may contribute to their formation include:
- Crohn’s disease: A chronic inflammatory condition affecting the digestive tract.
- Radiation therapy: High doses of radiation used to treat cancer can lead to fistulas.
- Diverticulitis: A condition causing small pouches to form in the digestive tract, which may become inflamed.
- Chronic constipation: Straining and skin tearing around the anus can result in a fistula.
- Trauma: Repeated or severe trauma to the anal area.
- Sexually transmitted diseases (STDs): Conditions like HIV can increase the risk of developing a fistula.
- Tuberculosis: Although rare, anal tuberculosis can lead to fistulas.
- Anal sex: In some cases, anal intercourse may be a contributing factor.
- Frequent diarrhea: This can irritate the anal region and cause fistulas to develop.
- Poor blood flow: A reduction in blood supply to the anorectal area.
Diagnosing an Anal Fistula
To diagnose an anal fistula, your doctor will review your medical history and examine the area around the anus. In some cases, the fistula is visible on the skin, but if not, further tests may be required. These include:
- Anoscopy: A procedure using a small tube to view the inside of the rectum and anus.
- Imaging tests: An ultrasound or MRI may be conducted to identify the fistula tract.
- Tests for Crohn’s disease: If an abscess is detected, additional testing, such as colonoscopy, blood tests, and x-rays, may be required to check for Crohn’s disease.
During a colonoscopy, the doctor uses a lighted, flexible instrument to examine the rectum and colon. A mild anesthetic will keep you awake but sedated during the procedure.
Treatment Options for Anal Fistula
While antibiotics may be prescribed to prevent or treat infection, surgery is often required to fully resolve an anal fistula. The goal of surgery is to remove the fistula while preserving the anal sphincter muscles to prevent incontinence. Some common surgical options include:
- Fistulotomy: Enlarging the fistula’s opening to promote surface-level healing. This is typically an outpatient procedure, allowing you to go home the same day.
- Seton placement: In more complex cases, a seton (a special drain made from suture or rubber) is placed around the fistula, tightening over time to promote healing and reduce the risk of incontinence.
- Filling the fistula: The surgeon may close the fistula’s inner opening with a surgical material and fill the fistula tunnel with a biodegradable substance that the body gradually absorbs.
- Stem cell therapy: If the fistula is related to Crohn’s disease, the doctor may inject stem cells into the affected area.
Preventing Anal Fistulas
While not all anal fistulas can be prevented, certain measures can reduce the risk:
- Keep the anal area dry and clean using warm water and mild soap.
- Treat diarrhea promptly to avoid irritation.
- Stay hydrated and eat a fiber-rich diet.
- Exercise regularly.
- Practice safe sex using condoms or other barrier methods to prevent sexually transmitted infections.
- Seek immediate treatment for any sexually transmitted infections.
- If you have an infant, change their diapers frequently to avoid infection.
Conclusion
Though managing an anal fistula can be challenging, it is treatable. Recognizing risk factors and monitoring for symptoms can help you seek medical care promptly and prevent complications. If you experience any of the symptoms mentioned, consult a healthcare provider as soon as possible.
