Anal Fistula
Anal fistula is a medical condition in which an abnormal small tunnel is developed that connects the bowel with the skin near the anus.
Anal Fistula
Symptoms of Anal Fistula
If you are suffering from anal fistula, you will experience one or more of the following symptoms:
- Pain and swelling around the anal area
- Difficulty in sitting and passing stool (feces)
- Redness, soreness, or itching of the skin around the anal opening
- Pus drainage near the anal opening
- Fever and generalized body pain


Symptoms of Anal Fistula
- Pain and swelling around the anal area
- Difficulty in sitting and passing stool (faeces)
- Redness, soreness, or itching of the skin around the anal opening
- Pus drainage near the anal opening
- Fever and generalized body pain
Causes of Anal Fistula
Most cases of anal fistula develop from an anal abscess. When one of the small glands present in or around the anus becomes blocked, an abscess is formed collecting pus. The abscess needs to be drained either by surgery unless it drains spontaneously. Untreated anal abscess may develop into a fistula.
Certain medical conditions increase the risk of fistula formation. These conditions include:
- Crohn’s disease
- Chronic diarrhea
- Diverticulitis
- Radiation treatment for rectal cancer
Risk Factors of Anal Fistula
Anal fistula is more commonly seen in patients with these conditions:
- Diabetes mellitus
- Compromised immune system
- Crohn’s disease
- Anal fissure
- Receptive anal sex
Prevention of Anal Fistula
Anal fistula can be prevented by timely treatment of anal abscesses.
Complications of Anal Fistula
- Repeated infections
- Sepsis
- Severe pain
- Infection spreading to nearby organs
Diagnosis of Anal Fistula
Your doctor will first take a detailed history and a physical examination to look for an external opening on the skin. Pus drainage can be often seen from the external opening. If an external opening is visible, your doctor will then try to determine the depth and direction of the fistula tract.
Your doctor may also perform a digital rectal examination (DRE). It is a simple bedside procedure in which your doctor will insert a gloved finger into your anus to look for any abnormality. Proctoscopy or anoscopy is also usually performed.
You doctor may also advise further testing to look for the openings of anal fistula. These tests may include:
- Ultrasound scan
- Magnetic resonance imaging (MRI) scan
- Computerized tomography (CT) scan
Treatment of Anal fistula
If you or someone you know is diagnosed with an anal fistula, a surgery is usually required to close off the fistula. Conservative management does not help much in healing of fistula.
Surgical Management of Anal Fistula
Different surgical options are available to treat anal fistula. Your doctor will discuss these options with you and advise you according to your general health and your condition. Most patients need general anesthesia for these procedures. The available options are:
- Fistulotomy: a procedure in which the whole length of the fistula is cut open so it heals into a flat scar.
- Seton procedure: a piece of surgical thread called a seton is placed in the fistula to accelerate the healing process and close off the fistula.
- Other techniques are also available. These include filling the fistula with special glue, blocking it with a special plug, or covering it with a flap of tissue
Follow Up
After surgery, you will be given appropriate pain killers. You will be advised to drink plenty of fluids and eat a high-fiber diet to prevent constipation. You should expect to have a bowel movement within 48 hours. This may initially be uncomfortable and painful. A small amount of bleeding or discharge is possible. You can resume your daily activities, provided you feel comfortable.