What are the causes and management of rectal pain?

Causes and Management of Rectal Pain

Rectal pain is most commonly caused by anorectal abscesses, anal fissures, thrombosed hemorrhoids, proctitis, and functional rectal pain disorders, with prompt diagnosis and targeted treatment essential for reducing morbidity and improving quality of life. 1

Common Causes of Rectal Pain

1. Anorectal Abscesses

• Presentation: Perianal pain, swelling, fever, and sometimes discharge
• Etiology: Most commonly from obstructed anal crypt glands, with pus collecting in various anatomical spaces
• Diagnosis: Based on history and physical examination; deeper abscesses may require imaging
• Management:
  • Prompt surgical drainage is essential
  • Antibiotics indicated for systemic signs of infection, immunocompromised patients, or significant cellulitis 1
  • Empiric broad-spectrum antibiotics covering Gram-positive, Gram-negative, and anaerobic bacteria when needed

2. Anal Fissures

• Presentation: Severe pain during and after defecation, often with bright red bleeding
• Location: Most commonly posterior midline of anal canal
• Management:
  • Initial treatment: High-fiber diet, stool softeners, sitz baths, topical anesthetics
  • For chronic fissures: Topical nitrates or calcium channel blockers
  • Surgical sphincterotomy for non-responsive cases 2

3. Hemorrhoids

• Presentation: Pain (especially when thrombosed), bleeding, itching, and lumps
• Management:
  • First-line: Fiber supplementation, adequate fluid intake, sitz baths
  • Acutely thrombosed external hemorrhoids should be excised if within 48-72 hours of pain onset 3
  • Advanced cases may require rubber band ligation or surgical hemorrhoidectomy 4

4. Proctitis

• Presentation: Rectal pain, tenesmus, discharge, urgency
• Etiology:
  • Infectious (sexually transmitted infections like gonorrhea, chlamydia, HSV)
  • Inflammatory bowel disease
  • Radiation-induced
• Management:
  • For suspected STI-related proctitis: Ceftriaxone 125 mg IM plus doxycycline 100 mg twice daily for 7 days 1
  • Specific treatment based on identified cause

5. Functional Rectal Pain

• Types: Proctalgia fugax (episodic severe pain), levator ani syndrome (chronic pain)
• Management: Warm baths, fiber supplementation, biofeedback therapy 2

6. Less Common but Serious Causes

• Rectal cancer: May present with pain, bleeding, change in bowel habits
• Perianal Crohn's disease: Complex fistulas, abscesses
• Rectal foreign bodies or trauma: May cause pain, bleeding, and perforation

Diagnostic Approach

1. Physical examination:

   • Visual inspection of perianal area
   • Digital rectal examination to assess sphincter tone and tenderness
   • Anoscopy to visualize the anal canal and distal rectum

2. Imaging (when indicated):

   • MRI is preferred for suspected complex fistulas, occult supralevator abscesses, or perianal Crohn's disease 1
   • CT scan may be useful in certain clinical scenarios
   • Endoanal ultrasound can help identify fistulas and abscesses

Management Principles

For Anorectal Abscesses:

1. Surgical drainage is the definitive treatment
2. Antibiotics when indicated:
   • Systemic signs of infection
   • Immunocompromised patients
   • Significant surrounding cellulitis
   • Incomplete source control 1

For Pain Management:

• Topical anesthetics: Lidocaine for temporary relief, especially during procedures 5
• Sitz baths: For symptomatic relief of most anorectal conditions
• Oral analgesics: NSAIDs as first-line; opioids should be used with caution due to risk of dependence and constipation 1

For Defecatory Disorders:

• Address underlying causes of constipation or diarrhea
• Pelvic floor exercises for incontinence 1
• Dietary modifications and adequate fluid intake

Special Considerations

• Immunocompromised patients: Higher risk of atypical infections and complications
• Inflammatory bowel disease: May have complex perianal disease requiring multidisciplinary management
• Postoperative pain: May indicate complications requiring prompt evaluation

Common Pitfalls

1. Missing serious pathology: Always consider rectal cancer in patients with persistent symptoms
2. Inadequate drainage of abscesses: Can lead to fistula formation or recurrence
3. Overuse of antibiotics: Not indicated for simple abscesses after adequate drainage
4. Delayed surgical referral: Necessary for complex or recurrent cases

By promptly identifying the cause of rectal pain and implementing appropriate management strategies, clinicians can significantly reduce morbidity and improve quality of life for patients with these common but often debilitating conditions.