What is Anal fistula: Symptoms, Treatment & Surgery

GetWellGo explains anal fistula symptoms, treatment options, and surgery. Find out how international patients can receive the best care for this condition.

What is Anal fistula: Symptoms, Treatment & Surgery

  • Category

    General

  • Published By

    GetWellGo Team

  • Updated on

    05-May-2025

Anal Fistula Symptoms

Anal fistula signs differ by severity but often consist of:

Primary Symptoms:

  • Chronic pain or discomfort: Particularly when sitting, during bowel movements, or walking.
  • Recurrent anal abscesses: Redness, swelling, and pus development around the anus.
  • Discharge: Pus or blood-tainted fluid leaking from an opening close to the anus.
  • Skin irritation: Caused by ongoing drainage, causing itching and redness.
  • Swelling or an open hole near the anus: With occasional pus or fluid leakage.
  • Foul-smelling discharge: From the outside opening of the fistula.
  • Fever and malaise: If there is infection or abscess formation.
  • Trouble having bowel movement: Or pain on defecation.

Less Common Symptoms:

  • Leakage of stool (in complex or multiple fistulae)
  • Passage of gas or stool from an outside opening
  • Constipation due to fear of pain

Anal Fistula Treatment

Anal fistula treatment options typically involve medical or surgical treatment. The decision is based on the type, complexity, and site of the fistula, and the general health of the patient.

Non-Surgical Treatments (for specific cases)

They are restricted in application and are usually temporary or adjunctive measures:

  • Antibiotics – Applied if there is infection but don't treat the fistula.
  • Fibrin Glue – A type of glue injected into the fistula to close it; low rate of success when fistulas are complex.
  • Plug Insertion – A plug that is collagen-based and inserted into the fistula to close the fistula; results are variable.
  • Seton Placement (temporary thread) – Assists with draining the infection and permits gradual healing; is left in for weeks or even months.

Surgical Treatments (more thorough and effective):

Fistulotomy

  • Procedure: The fistula tract is opened and flattened to heal from the inside out.
  • Used for: Low, simple anal fistulas.
  • Success: Very high; very low recurrence.

Seton Placement (cutting or draining seton)

  • Procedure: A string is inserted through the fistula to maintain it open and drain or have it cut through by degrees into the muscle.
  • Used for: Complex or high fistulas where cutting in one operation may jeopardize incontinence.

LIFT Procedure (Ligation of Intersphincteric Fistula Tract)

  • Procedure: The internal opening is ligated through a tiny cut in the anal sphincter area.
  • Used for: Complex or high fistulas.
  • Success: Good healing and continence maintenance balance.

Advancement Flap Surgery

  • Procedure: The internal opening is closed by a flap of healthy tissue.
  • Used for: Recurrent or high-risk fistulas.
  • Success: Moderate to high.

Laser (FiLaC – Fistula Laser Closure)

  • Procedure: A tract is sealed with a laser probe.
  • Used for: Chosen cases; minimally invasive.
  • Success: Promising but variable.

Anal Fistula Surgery

Anal fistula surgery is generally necessary for a permanent fix, particularly when the fistula won't close up by itself. The aim is to close or fix the fistula without causing damage to the anal sphincter muscles since this may result in incontinence. Following is an overview of the standard surgical procedures:

Fistulotomy

  • The tract of the fistula is cut open and is permitted to heal from the inside out.
  • The external opening is not closed but left open to drain, and the internal opening is closed surgically.

Seton Placement (for Complex Fistulas)

  • A thin operative thread (Seton) is inserted through the fistula tract to maintain the fistula open and permit drainage.
  • The Seton is left in situ for an extended duration (weeks or months) to facilitate slow healing and progressive cutting through the sphincter muscle.

LIFT Procedure (Ligation of Intersphincteric Fistula Tract)

  • A tiny cut is given in the perineum (the region between the anus and genitals), and the fistula tract is located. The internal opening is closed off while leaving sphincter muscles intact.

Advancement Flap Surgery

  • The fistula's internal opening is closed by healthy tissue (a flap) taken from the surrounding tissue.
  • The flap is sewn into place, closing off the internal opening.

Laser Surgery (FiLaC – Fistula Laser Closure)

  • A laser fiber is utilized to seal the fistula tract from the inside.
  • The laser energy is focused along the tract to assist in healing and sealing.

Anal Abscess and Fistula

Anal Abscess

Anal Abscess is an aching lump of pus developing near the anus as a result of an infection of one of the anal glands. It arises when a tiny gland along the anal canal is obstructed and leads to puffiness and the development of pus.

Anal Fistula

An anal fistula is a pathological tunnel or tract that develops between the skin over the anus and the canal of the anus (anal canal), usually from an unhealed or incompletely healed anal abscess. A fistula is essentially an abscess that has not properly healed.

Anal Fistula Causes

An anal fistula is an abnormal tunnel or pipe that develops between the inside of the anus or rectum and the surrounding skin of the anus. It usually arises from an anal abscess (an infection), but there are several other factors and conditions that may lead to the development of an anal fistula. A look at the common causes is what follows:

  • Anal Abscess
  • Crohn's Disease
  • Previous Surgery or Trauma
  • Sexually Transmitted Infections (STIs)
  • Tuberculosis (TB)
  • Cancer
  • Radiotherapy
  • Foreign Objects or Infections
  • Diabetes

Anal Fistula Diagnosis

Diagnosis of an anal fistula requires a mix of clinical assessment, imaging procedures, and at times further intervention to clearly determine the location, complexity, and causality of the fistula. This is a general outline of the standard diagnostic process:

Medical History

  • Symptoms review: Your physician will inquire about your symptoms, such as pain, drainage, or repeated abscesses around the anus.
  • Previous medical conditions: Medical history of Crohn's disease, IBD, anal abscess, surgery, or trauma is relevant.
  • Risk factors: Knowledge about sexually transmitted diseases (STIs), a history of diabetes, or cancer can be useful in trying to limit the cause.

Physical Examination

  • Visual inspection: The physician will look visually at the skin around the anus for any external openings, skin tags, or infections.
  • Palpation: Through feeling with the fingers around the anal area, the physician can try to find an abscess or areas of tenderness, swelling, or an abnormal opening from a fistula.
  • Digital rectal exam: The physician might insert a gloved finger into the rectum to check for any irregularities or internal openings related to the fistula.

Anoscopy

  • Procedure: A short, lighted tube (anoscope) is placed in the anus to examine the internal opening of the fistula. This might allow the physician to observe whether or not the fistula is connected to the anal canal.
  • Benefit: Offers a direct view of the inner anatomy of the anal area, which may assist in detecting easier fistulas.

Imaging Studies

Imaging is particularly beneficial in complex fistulas involving the sphincter muscles or more than one tract, and to evaluate the fistula's location and depth. The most frequent imaging methods are:

a. MRI (Magnetic Resonance Imaging)

  • Most reliable way of visualizing the fistula anatomy, particularly when it extends into the anal sphincters or is complex.
  • Can measure the size of the fistula, its relationship to the surrounding tissues, and any related abscesses or inflammation.
  • First choice for complex cases or those involving Crohn's disease.

b. Endoanal Ultrasound (EAUS)

  • Utilizes sound waves to produce high-resolution images of the anal canal and sphincter muscles.
  • Beneficial for low to moderately complex fistulas, especially if MRI is not an option or required.
  • Can define the fistula's relationship with the anal sphincters.

c. Fistulogram

  • X-ray with contrast: A contrast agent is injected into the fistula, and X-rays are obtained to follow the course of the fistula.
  • Less utilized today, as MRI and ultrasound become more prevalent, but it still may be useful in certain instances.

Proctoscopy or Colonoscopy

  • Proctoscopy: A more recent variation of anoscopy, in which a deeper penetration into the rectum can be obtained to assess any intra-anal involvement of the fistula.
  • Colonoscopy: If a disease such as Crohn's disease or IBD is suspected, a colonoscopy can be employed to examine the entire colon and rectum for evidence of inflammation or other pathology that might result in fistula formation.

Examination under Anaesthesia (EUA)

  • Indication: If a fistula is complex or cannot be evaluated by other means, the physician may order a EUA. This includes sedating the patient while the physician performs a complete examination of the anus, rectum, and the areas around them.
  • Procedure: In EUA, the physician might employ a fistula probe (a slender device) to follow the fistula tract, ascertain its direction, and inspect for any internal openings.

Differential Diagnosis

The physician will also exclude other conditions that may produce similar symptoms, including:

  • Hemorrhoids
  • Anal fissures
  • Abscesses (without fistula)
  • Rectal cancer
  • Sexually transmitted diseases (in anal ulcers or abscesses)

Anal Fistula Surgery Recovery

Fistulotomy Recovery:

  • Healing will take 4–6 weeks, but complete closure of the wound can take as long as 2 months.
  • You might have some discomfort for a few weeks while the wound heals.

Seton Surgery Recovery:

  • If a Seton (drainage string) is inserted, initial healing time can take several weeks, with the Seton remaining in place for several months. The Seton is tightened slowly to gradually cut through the tissue.
  • Healing will take 3–6 months for closure, depending on the level of complexity of the fistula.

Advancement Flap Surgery:

  • Recovery from advancement flap surgery will take 6–8 weeks. This technique uses healthy tissue to cover over the internal fistula opening and takes longer for the tissue to heal.

Anal Fistula Recurrence

Recurrence of an anal fistula can occur because of the incomplete healing, complex anatomy of the fistula, infection, or a predisposing underlying condition such as Crohn's disease. To prevent recurrence, proper post-surgical care should be adhered to, a high-fiber diet should be taken, underlying health conditions should be controlled, and activities that can cause stress on the healing site should be avoided. Recurrence can be treated with further surgery, Seton placement, or other specialized treatments.

Anal Fistula Complications

Anal fistula surgery and the disease itself can cause a number of complications, ranging from mild to severe. These complications should be identified early so that they can be treated in time to prevent worsening of symptoms or more severe health complications. Below is a list of the potential complications of anal fistulas:

  • Infection
  • Recurrence
  • Fecal Incontinence
  • Bleeding
  • Pain and Discomfort
  • Abscess Formation
  • Stricture (Narrowing) of the Anus
  • Delayed Healing
  • Formation of Fistula After Surgery (New Fistula)

Anal Fistula Management

Treatment of an anal fistula requires a series of medical treatment, surgery, and lifestyle adjustment to cure the fistula, prevent recurrence, and treat associated complications. Treatment is based on the complexity of the fistula, cause (such as infection or Crohn's disease), and the condition of the patient. The following is a broad description of management of anal fistulas in general:

  • Initial Evaluation and Diagnosis
  • Medical Management
  • Surgical Management
  • Post-surgical Care and Recovery
  • Lifestyle and Dietary Changes
  • Preventing Recurrence
  • Long-term Management


 

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