Fistula Treatment: Understanding Anal Fistula and Its Surgery

An anal fistula is a small, abnormal tunnel that forms between the inside of the anal canal and the skin near the anus, usually following an infection. It rarely heals on its own, and surgery is almost always required to close it for good.

What Is an Anal Fistula?

An anal fistula (commonly called "bhagandar" in Hindi) is an abnormal narrow tunnel that develops between the inside of the anal canal and an opening on the skin near the anus. It almost always begins as an anal abscess — a pocket of infection in one of the small glands inside the anal canal — that doesn't fully heal after draining, leaving behind a persistent tract lined with infected tissue.

What Causes an Anal Fistula?

• Anorectal abscess — the most common cause, where an infected gland forms a pocket of pus that tracks outward under the skin
• Inflammatory bowel disease, such as Crohn's disease, which makes fistulas more likely and more complex
• Tuberculosis, particularly in regions where TB is more common
• Previous anorectal surgery or trauma
• Chronic anal fissures that become infected

Fistulas form near small glands inside the anal canal

Signs and Symptoms

• Persistent, often foul-smelling discharge of pus or blood from an opening near the anus
• Recurrent swelling, pain, and redness around the anus
• Irritation or itching of the skin around the fistula opening
• Pain that may worsen with bowel movements, sitting, coughing, or movement
• Fever, particularly if an abscess is actively forming

How Fistula Surgery Works

1. Diagnosis and mapping. Before surgery, the surgeon identifies the fistula's path — from its internal opening in the anal canal to its external opening on the skin — often with an examination under anesthesia, and sometimes an MRI or ultrasound for complex cases.
2. Fistulotomy. For simpler, low fistulas that don't involve much of the sphincter muscle, the tract is simply laid open along its entire length so it can heal from the inside out — this is the most common and effective technique.
3. Seton placement. For fistulas that pass through a significant portion of the anal sphincter, a soft surgical thread (seton) may be placed through the tract to drain it gradually and help preserve continence, sometimes as a staged approach before definitive treatment.
4. Advanced techniques. For complex fistulas, options like LIFT (ligation of the intersphincteric fistula tract), fibrin glue, fistula plugs, or laser fistula closure can be used to close the tract while minimizing damage to the sphincter muscles that control continence.

Recovery

• First 1–2 weeks: Some discomfort and drainage are expected as the open wound (in a fistulotomy) begins healing from the inside out.
• Wound care: Regular sitz baths and dressing changes are typically needed until the wound fully closes.
• Full healing: Depending on the complexity of the fistula and technique used, complete healing can take anywhere from a few weeks to a couple of months.

Risks and Considerations

• Recurrence, particularly with complex or high fistulas
• Risk of affecting continence if a significant amount of sphincter muscle is involved in the surgery
• Bleeding or infection
• Delayed wound healing

The right surgical approach depends heavily on exactly how the fistula tracks relative to the anal sphincter, which is why proper mapping before surgery matters so much.

The anal canal is the final segment of the digestive tract

The Takeaway

Anal fistulas don't heal on their own and reliably need surgical treatment, but modern techniques have made it possible to close even complex fistulas while protecting continence. If you're dealing with recurring pain, swelling, or discharge near the anus, prompt evaluation by a colorectal specialist can prevent repeated abscesses and get you on the path to a lasting fix.