What Are Perianal Abscess and Fistula?

A perianal abscess, also known as an anal abscess, forms around the anus and appears as a pus-filled swelling near the anal region. Pain, fever, and constipation are among the symptoms of an anal abscess. Typically, an anal abscess occurs when a gland inside the anus becomes blocked or obstructed. To relieve the pain and symptoms, the abscess must be drained. If left untreated, it can cause significant pain that interferes with daily life. If the abscess drains into the large intestine or through the skin, this is called a fistula.

An anal abscess, which is an infectious condition, can develop due to the blockage of glands located around the anus. The accumulated secretions caused by the blockage become infected by local bacteria. In children, untreated anal fissures can also become infected and turn into an abscess. The cause of these blockages is often unknown. However, due to frequent stool contamination, long-term and regular treatment is required, and surgical intervention is often necessary.

In infants without underlying causes, symptoms are usually mild. Mild fever, pain, and redness may occur. Eventually, the abscess opens and drains, relieving the symptoms. After a few weeks, discharge may recur intermittently. However, most cases resolve spontaneously before the age of two. Fistulas develop in 10–20% of perianal abscesses. A fistula can also appear without a prior abscess. About 15–20% of fistulas are multiple.

What Are the Causes of Perianal Abscess in Children?

• A weakened immune system
• Poor hygiene
• Constipation and strained bowel movements
• Anal fissures
• Congenital anomalies, etc.

What Are the Clinical Symptoms of Anal Abscess?

The most prominent symptoms of an anal abscess are pain, swelling, and itching in the affected area. In addition, warmth in the anal region and general fatigue may occur due to the abscess. In summary, the symptoms include:

• A painful, throbbing swelling
• Pain that worsens while sitting, coughing, or defecating
• Pus-like discharge from the anal area
• Pain in the rectum or anus
• A red swelling
• Painful bowel movements and constipation
• Rectal bleeding
• Pain in the lower abdomen

How Are Perianal-Perirectal Abscesses Classified?

1. Perianal Abscess: The most common type. Presents as a swelling at the junction of the anus and the skin.
2. Ischiorectal Abscess: Detected via rectal examination. Not visible from the skin surface.
3. Ischiorectal (Ischioanal) Abscess: Infection in the intersphincteric space penetrates the external sphincter and spreads to the ischiorectal fossa. Can reach large volumes but is not visible externally.
4. Supralevator (Pelvic) Abscess: Quite rare, usually associated with Crohn's disease.
5. Horseshoe Abscess: A bilateral ischiorectal abscess connected behind the rectum.

How Is an Anal Abscess Diagnosed?

The diagnosis is made based on medical history and physical examination. However, to confirm the diagnosis and monitor treatment, every patient undergoes ultrasonography, blood tests, and abscess culture.

In chronic cases or in patients suspected of having a fistula extending to the bowel (anus and rectum) and deep tissues, Magnetic Resonance Imaging (MRI) is used. In some patients, a test called fistulography may be performed, where contrast dye is injected into the fistula opening and an X-ray is taken.

Is Colonoscopy Necessary for Anal Abscess?

Very rarely, in cases where a fistula is suspected, colonoscopy may be performed to assess the fistula’s level.

How Is an Anal Abscess Treated?

If the abscess is not yet mature (i.e., not ready to be drained), treatment begins with antibiotics and pain relievers. This may sometimes require hospitalization for intravenous therapy.

If the abscess is mature, the primary treatment is surgical drainage. This procedure may need to be performed under anesthesia in an operating room. A culture test is sent during the drainage. Since the abscess causes intense pain, drainage typically provides significant relief for the patient.

Are There Any Post-Drainage Instructions?

Draining the abscess does not complete the treatment; it is just the beginning. Further steps include:

• Sitting in warm water with Betadine for 10 minutes, several times a day. This also helps relieve pain.
• Antibiotics are given to treat infection; in some cases, intravenous administration is required.
• For constipated patients, stool softeners are prescribed.
• Painkillers are used.

What Are the Complications of a Perianal Abscess?

Complications of untreated or inadequately treated perianal abscess include:

• Fistula
• Recurrence of the abscess
• Immune system disorders
• Inflammatory bowel diseases
• Sepsis

Can Anal Fistulas Be Classified?

Yes. Anal fistulas are classified based on their location in the anal canal:

• Intersphincteric fistula (50%)
• Transsphincteric fistula (30%)
• Suprasphincteric fistula (10%)
• Extrasphincteric fistula (3%)
• Horseshoe fistula (3–7%)

How Is Perianal Fistula Diagnosed?

The diagnosis is made based on medical history and physical examination and is confirmed using imaging methods. Imaging techniques are similar to those used for perianal abscess (ultrasound, Magnetic Resonance Imaging, fistulogram, colonoscopy).

What Are the Clinical Findings of Perianal Fistula?

If not infected, there may be no clinical symptoms. In children, the fistula may sometimes be congenital and appear only as an opening on the skin. Since most fistulas develop after a perianal abscess, a history of such an abscess is often present.

If it becomes infected, symptoms of infection such as painful defecation, discharge from the anus, swelling, and throbbing around the anus are observed.

How Is Perianal Fistula Treated?

A perianal fistula does not heal on its own. If infected, the infection is treated first. Then surgery is performed. Surgical options include fistulotomy, fistulectomy, and Seton placement.

Additionally, weight loss, warm sitz baths, hygiene, and some local applications are recommended.

Is Laser Used in the Treatment of Perianal Fistula?

It is commonly and successfully used in adults. However, in children, due to technical limitations, there is not yet sufficient experience.

Can Cancer Develop from a Perianal Fistula?

In untreated cases, it has been shown that cancer may develop in the fistula area over time.

Can Anal Fistula Recur After Treatment?

After treatment, the patient must follow their doctor's recommendations and attend follow-up appointments. Otherwise, recurrence is possible, and further surgery may be required.

*** The information provided here is organized for the purpose of informing visitors to the website. None of the content should be considered as medical advice or lead to any decision or action. Families should have their child examined by a pediatric surgery specialist and consult directly with them before making any decisions.