An anal fistula is a small tunnel that connects an internal opening in the anal canal to an opening on the skin near the anus. It usually develops after an infection or abscess in the anal glands and often causes pain, discharge and irritation that do not go away on their own. As a dedicated liver and gastroenterology hospital in Dhantoli, Nagpur, LGI Hospitals provides evaluation and treatment of anal fistula through a team of medical gastroenterologists and a GI surgeon experienced in colorectal and anorectal surgery.
What is an anal fistula?
- An anal fistula is an abnormal channel between the end of the bowel and the skin around the anus.
- Most fistulas start from infected anal glands; the infection forms an abscess and, when it drains, a tunnel may remain behind as a fistula.
Doctors classify anal fistulas as an anorectal condition, describing them as simple (single, straight tract) or complex (multiple branches, higher tracts, or linked to other diseases).
Anal fistula symptoms
Common symptoms of an anal fistula include:
- Persistent skin irritation or itching around the anus.
- A small opening or “pimple‑like” area near the anus that may ooze pus, blood or stool.
- Throbbing pain around the anus, often worse when sitting, walking or passing stool.
- Swelling or a tender lump near the anus, sometimes with fever if an abscess is present.
- Occasional difficulty controlling gas or stool in some complex cases.
If symptoms return after an earlier anal abscess or surgery, they strongly suggest a fistula has formed and a specialist should check it.
What causes an anal fistula?
The most common cause is infection of the anal glands (cryptoglandular infection), which can lead to a perianal abscess and then a fistula. Other important causes and risk factors include:
- Inflammatory bowel disease – especially Crohn’s disease, which can create deep ulcers and tracts around the anus.
- Previous perianal abscess – even when drained, many abscesses later develop into a fistula.
- Infections such as tuberculosis or certain sexually transmitted infections, which may affect the anorectal area.
- Trauma or surgery near the anus, including childbirth‑related injury or previous anorectal operations.
- Weakened immune system or chronic conditions that make infections more likely.
In many people, more than one factor can be present, so a detailed medical history helps guide evaluation and treatment.
How is an anal fistula diagnosed?
Diagnosis usually starts with a consultation with a colorectal or GI surgeon.
Clinical evaluation
- History of symptoms such as pain, discharge, swelling and any previous abscess or anorectal surgery.
- Examination of the area around the anus to look for external openings, redness, swelling and discharge.
- Digital rectal examination or anoscopy / proctoscopy to assess the internal opening and rule out other conditions.
Imaging and additional tests
When the fistula is complex or not clearly visible, doctors may recommend:
- MRI of the pelvis or MRI fistulogram to map the course of the fistula and its branches.
- Endoanal ultrasound in some cases to see how the tract relates to the anal sphincter muscles.
- Blood tests or screening for inflammatory bowel disease or infections if suspected from the history.
Accurate mapping of the tract is important to choose the best treatment while protecting continence.
Anal fistula treatment options
Anal fistulas rarely heal on their own, so treatment usually involves a procedure or surgery designed to drain infection, close the tract and protect the anal sphincter.
1. Seton placement
- A thin piece of surgical thread or similar material is passed through the fistula tract and tied into a loop.
- It keeps the tract open to drain infection and may be left for weeks or months, sometimes as a step before further surgery.
2. Fistulotomy and fistulectomy
- Fistulotomy: the tract is laid open along its length so it can heal from the inside out.
- Fistulectomy: the tract is completely excised; this can have high success for low fistulas in experienced hands.
- These methods work well for simple, low tracts but must be planned carefully to avoid harming the sphincter muscles.
3. Sphincter‑sparing and minimally invasive procedures
For higher or complex fistulas, techniques that try to preserve the sphincter are often preferred, such as:
- Ligation of the intersphincteric fistula tract (LIFT) – the tract is tied off and divided in the intersphincteric plane.
- Advancement flap procedures – the internal opening is covered with a flap of healthy tissue to encourage closure.
- Biomaterial plugs and fibrin glue – special plugs or glue are placed in the tract after cleaning to help seal it.
- Fistula laser closure or video‑assisted techniques, which use energy or endoscopic guidance to treat the tract from the inside.
Each approach has different healing rates and risks of recurrence or incontinence, so surgeons choose based on fistula type, patient health and previous treatments.
Recovery and life after anal fistula surgery
Recovery depends on the exact procedure and whether the fistula was simple or complex.
- Pain and discomfort are common for a few days but usually improve with pain relief, sitz baths and good hygiene.
- Doctors often recommend fibre‑rich diet, plenty of fluids and stool softeners to make bowel movements more comfortable.
- Most people can resume light activities within several days, but complete healing of the wound or tract can take a few weeks or longer.
- Follow‑up visits allow the surgeon to check healing, watch for recurrence and adjust care if there are continence issues or ongoing drainage.
Ignoring symptoms or delaying treatment can lead to repeated infections, new branches of the fistula and more complex surgery later, so early consultation is important.
Anal fistula care at LGI Hospitals, Nagpur
LGI Hospitals in Dhantoli, Nagpur is a dedicated single‑speciality centre for liver, gastroenterology and digestive surgery. The clinical team includes three senior medical gastroenterologists and one GI surgeon, with expertise across hepatology, luminal gastroenterology, interventional endoscopy and colorectal surgery.
Within surgical gastroenterology, the hospital manages a range of colorectal and anorectal conditions, including operations for piles, fissure and fistula, alongside advanced endoscopic and imaging services in the same facility. This set‑up allows patients with anal fistula to receive diagnostic evaluation, imaging, endoscopic treatment and surgery in a coordinated, team‑based manner.
When to see a doctor for anal fistula symptoms
You should seek medical advice from a gastroenterologist or colorectal / GI surgeon if you notice:
- Persistent pain, swelling or a lump near the anus
- Repeated episodes of anal abscess or discharge of pus or blood from the skin around the anus
- Ongoing skin irritation, bad smell or trouble sitting due to anal discomfort
- History of Crohn’s disease, tuberculosis or previous rectal surgery with new symptoms around the anus
A specialist can confirm whether an anal fistula is present, explain treatment options and help choose a plan that balances cure rates with protection of bowel control.
Frequently asked questions about anal fistula
What is an anal fistula?
An anal fistula is a small tunnel that forms between the anal canal and the skin near the anus, usually after an infection or abscess in the anal glands.
What are the first signs of an anal fistula?
Early signs often include irritation and pain around the anus, a small opening or lump that leaks pus or blood, and discomfort that gets worse when sitting or passing stool.
Can an anal fistula heal without surgery?
Most anal fistulas do not heal on their own, so doctors usually perform surgery or procedures like seton placement or sphincter-sparing techniques to close the tract and prevent recurrent infection.
Is anal fistula surgery painful?
You can expect some pain after surgery, but medicines, warm sitz baths, and stool softeners usually manage it well, and the discomfort steadily improves as the wound heals.
Does anal fistula always come back?
A single, well-planned operation cures many people, but complex or high fistulas carry a higher risk of recurrence, so surgeons must ensure proper follow-up and choose the technique carefully.