Anorectal Abscess and Perianal Fistula

Anorectal abscess and perianal fistula are two serious health problems that develop around the anus, are inflammatory, and are often a continuation of each other. These diseases proceed with pain, discharge, and a significant decrease in quality of life. If left untreated, recurrent inflammation, complications, and more complex surgical requirements may arise. With early diagnosis and appropriate surgical treatment, these diseases can largely be controlled.

What Is an Anorectal Abscess?

An anorectal abscess is an inflammatory, purulent sac structure that develops in the tissues around the anus. It usually forms as a result of blockage and infection of glands in the anal canal. It progresses with an acute presentation and requires rapid intervention.

Types of Abscesses

There are different types according to location:

  • Perianal abscess: Subcutaneous in the area around the anus, the most common type
  • Ischiorectal abscess: On the lateral wall of the anus, deeper
  • Intersphincteric abscess: Between the internal and external sphincter muscles
  • Supralevator abscess: Deepest location, above the levator muscle

What Is a Perianal Fistula?

A perianal fistula is an abnormal channel structure formed between the anal canal and the skin around the anus. It usually develops after anorectal abscess drainage or emerges as a continuation of chronic infection.

Fistula Types (Parks Classification)

  • Intersphincteric fistula: Most common type (70%), passes through internal sphincter
  • Transsphincteric fistula: Involves both sphincter muscles
  • Suprasphincteric fistula: Passes above the sphincters
  • Extrasphincteric fistula: Encircles the sphincters externally, rarest

Simple and Complex Fistulas

  • Simple fistula: Single channel, little sphincter involvement
  • Complex fistula: Multiple channels, wide sphincter involvement, recurrent

Causes of Anorectal Abscess and Fistula

Main Causes

  • Blockage and infection of anal glands (most common cause, 90%)
  • Sexually transmitted infections
  • Inflammatory bowel diseases (Crohn's disease, ulcerative colitis)
  • Tuberculosis
  • Tumors
  • Post-trauma or surgery

Risk Factors

  • Inflammatory bowel diseases
  • Diabetes
  • Immune system weakness (HIV, chemotherapy)
  • Chronic constipation or diarrhea
  • Anal intercourse
  • Male gender (3-4 times more common)
  • Age 20-50
  • Family history
  • Smoking

Symptoms

Anorectal Abscess Symptoms

  • Severe, throbbing pain around the anus
  • Pain that increases with sitting, movement, and defecation
  • Swelling, redness, and warmth in the area
  • Fever and chills
  • Weakness and general discomfort
  • Difficulty urinating (in deep abscesses)
  • Constipation (due to pain)
  • Spontaneous discharge of inflammatory fluid in some cases

Perianal Fistula Symptoms

  • Continuous or intermittent discharge around the anus (pus, blood, or clear fluid)
  • Foul odor
  • Skin irritation and itching
  • Intermittent pain attacks
  • Recurrent abscess formation
  • Small opening on the skin (fistula mouth)
  • Stains on underwear
  • Hardness or lump around the skin

Diagnostic Methods

Physical Examination

  • Visual examination (evaluation of external fistula mouth)
  • Digital rectal examination
  • Regional pain, tenderness, and temperature check

Anoscopy and Rectoscopy

  • Direct imaging of the anal canal
  • Detection of internal fistula mouth
  • Evaluation of accompanying diseases

Imaging Methods

Endoanal Ultrasound
  • Evaluation of sphincter structure
  • Mapping of fistula channel
  • Abscess localization
Pelvic MRI
  • Gold standard in complex fistulas
  • Detailed anatomical mapping
  • Evaluation of sphincter involvement
  • Critical for surgical planning
Fistulography
  • Imaging of fistula tract with contrast material
  • Less preferred today

Additional Examinations

  • Blood tests (CRP, blood count)
  • Wound culture
  • Colonoscopy in Crohn's disease suspicion

Anorectal Abscess Treatment

Surgical Drainage (Emergency)

The foundation of anorectal abscess treatment is emergency surgical drainage:

  • Antibiotic therapy alone is not sufficient
  • Performed under local or general anesthesia
  • Purulent content is drained with a small incision
  • Wound is left open for secondary healing
  • Fistula may develop in 50% of cases after drainage

Antibiotic Treatment

  • Not sufficient alone, used as supportive after drainage
  • Required in diabetic, immunocompromised patients
  • Broad-spectrum antibiotics are preferred

Postoperative Care

  • Warm sitz baths
  • Wound dressings
  • Pain control
  • Stool softener laxatives

Perianal Fistula Treatment

The foundation of fistula treatment is surgical. It does not heal on its own. Treatment selection is based on fistula complexity.

Fistulotomy (Lay-Open Technique)

  • The oldest and most effective method
  • Cut open along the fistula channel
  • Preferred in simple, superficial fistulas
  • High success rate (95%)
  • Risk: Incontinence in complex cases (gas/stool leakage)

Seton Placement

A method that preserves the sphincter muscle. There are two types:

Loose (Drainage) Seton
  • Plastic or silicone thread is passed through the fistula
  • Continuously drains discharge
  • Controls inflammation
  • Temporary solution, then definitive treatment is performed
Cutting (Tightening) Seton
  • Cuts the fistula gradually by slowly tightening the thread
  • Reduces incontinence risk by slowly dividing sphincter muscle
  • Treatment may take months

Mucosal Flap Technique

  • The fistula mouth is closed with anal canal mucosa while preserving the sphincter muscle
  • Preferred in complex and high fistulas
  • Success rate 60-80%

LIFT Technique (Ligation of Intersphincteric Fistula Tract)

  • Fistula is ligated and cut from the intersphincteric area
  • Modern sphincter-preserving method
  • Success rate 60-90%
  • Low incontinence risk

Laser Treatment (FiLaC)

A laser fiber is placed inside the fistula channel to destroy the tissue:

  • Minimally invasive
  • Preserves sphincter muscle
  • Fast recovery
  • Success rate 60-75%
  • Repeatable

Fibrin Glue

  • Biological adhesive applied to fistula channel
  • Sphincter-preserving
  • Low success rate (30-50%)
  • Usually used with additional methods

Anal Fistula Plug

  • Biological or synthetic material placed in the fistula
  • Sphincter-preserving
  • Moderate success rate (40-60%)

VAAFT (Video-Assisted Anal Fistula Treatment)

  • Imaging and treatment from inside the fistula with an endoscope
  • The newest minimally invasive method
  • Useful in complex cases

Post-Operative Process

First Days

  • Warm sitz baths (3-4 times a day)
  • Attention to wound cleanliness
  • Use of painkillers
  • Use of stool softener laxatives

First Week

  • Return to light activities
  • Dressing changes
  • Attention to hygiene

First Month

  • Sports after 3-4 weeks
  • Sexual life after 2-3 weeks
  • Full recovery in 4-8 weeks
  • Regular check-ups are important

Possible Complications

Surgical Complications

  • Bleeding
  • Wound infection
  • Incontinence (gas or stool leakage) - Most feared complication
  • Wound dehiscence
  • Anal stenosis (narrowing)

Late Complications

  • Fistula recurrence (recurrence rate 10-30%)
  • Chronic pain
  • Delayed wound healing
  • Anal sexual dysfunction

Prevention and Lifestyle

Nutrition

  • Fiber-rich food consumption
  • Adequate fluid intake (2-2.5 liters per day)
  • Regular meals
  • Preventing constipation

Hygiene

  • Keeping the anal area clean
  • Gentle cleaning (avoiding irritating products)
  • Warm sitz baths (in case of symptoms)
  • Use of cotton underwear

Lifestyle

  • Smoking cessation
  • Healthy weight control
  • Regular exercise
  • Avoiding prolonged sitting
  • Prevention of constipation
  • Control of accompanying diseases

FAQ

No. Anorectal abscess definitely requires surgical drainage. Antibiotics alone are not sufficient; they are only used as supportive after drainage or in high-risk patients. Delayed drainage may lead to serious complications.

No, but the risk is high. Fistula develops in approximately 50% of cases after anorectal abscess drainage. Therefore, patients should be monitored for fistula development.

This risk has been greatly reduced with modern sphincter-preserving techniques. Incontinence is rare in simple fistulas. The risk increases in complex fistulas, but techniques such as LIFT, mucosal flap, and seton used by experienced surgeons minimize this risk.

No. Perianal fistula does not heal on its own because it has a permanent channel structure. When left untreated, it leads to recurrent inflammation, pain, and complex fistula development.

It varies according to the type of surgery. Return to work is possible within 5-7 days after simple fistulotomy, and within 2-3 weeks in complex cases. Desk workers can return earlier, those doing physical work later.