Anal pain

Introduction

Anal pain refers to discomfort or aching felt in and around the anal canal and rectum.

• May be sharp, burning, throbbing, or dull.

• Can be acute (sudden onset, e.g., fissure, thrombosed hemorrhoid, abscess) or chronic (long-term, e.g., fistula, malignancy, neuropathic pain).

• Accurate evaluation is essential because some causes are simple, while others require urgent surgical or oncological intervention.

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Causes of Anal Pain

1. Local Anorectal Conditions

• Anal fissure (most common): tear in the anal canal mucosa → sharp pain during/after defecation.

• Hemorrhoids: thrombosed external hemorrhoids cause severe, tender swelling.

• Perianal abscess: infection in anal glands causing severe throbbing pain, swelling, fever.

• Anal fistula: chronic discharge and intermittent pain.

• Proctitis: inflammation from infection (gonorrhea, chlamydia, herpes) or radiation.

• Anal cancer: persistent pain, bleeding, mass.

2. Gastrointestinal / Systemic Causes

• Inflammatory bowel disease (Crohn’s, ulcerative colitis): perianal ulcers, fistulas.

• Diverticulitis with perirectal involvement.

• Constipation with hard stools.

3. Neurological / Musculoskeletal Causes

• Pudendal neuralgia: chronic nerve pain in perineum.

• Levator ani syndrome: spasm of pelvic floor muscles.

• Coccygodynia: pain from tailbone radiating to anal region.

4. Trauma / Iatrogenic

• Injury from surgery, anal intercourse, foreign body.

• Complications of hemorrhoid treatment (banding, sclerotherapy).

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Clinical Features

• Fissure: sharp, cutting pain with defecation, blood on toilet paper.

• Thrombosed hemorrhoid: sudden, severe pain with tender bluish lump.

• Abscess: constant, throbbing pain, swelling, fever.

• Fistula: recurrent pain + pus/blood discharge.

• Cancer: persistent dull pain, mass, bleeding, weight loss.

• Neuropathic: burning/aching, not linked to bowel movements.

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Diagnostic Approach

1. History

• Onset, duration, character of pain.

• Relation to defecation, fever, discharge, bleeding.

• Past history: IBD, STIs, trauma, surgery.

• Bowel habits, constipation, diarrhea.

2. Examination

• Inspection: fissures, hemorrhoids, swelling, redness, external fistula openings.

• Digital rectal exam (unless too painful): tenderness, masses, tone.

• Proctoscopy/anoscopy if tolerated.

3. Investigations

• Blood tests: CBC, CRP (infection), glucose (diabetes risk).

• Stool tests: culture if infectious cause suspected.

• Imaging:

  • Ultrasound or MRI pelvis (fistulas, abscesses).

  • Colonoscopy (if bleeding, cancer suspicion, IBD).

• Biopsy: if suspicious lesion or mass.

• STI screening: syphilis, gonorrhea, chlamydia, herpes, HIV.

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Management and Treatment

Treatment depends on the underlying cause.

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A. General Measures (for many patients)

• Warm sitz baths (10–15 min, 2–3 times daily).

• High-fiber diet and hydration to soften stools.

• Stool softeners: Lactulose 10–20 mL orally once or twice daily, or Docusate sodium 100 mg orally twice daily.

• Analgesics:

  • Paracetamol 500–1000 mg every 6–8 h (max 4 g/day).

  • Ibuprofen 400 mg every 8 h if no contraindication.

• Topical soothing agents (zinc oxide, petroleum jelly).

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B. Specific Treatments

1. Anal Fissure

• Conservative: fiber, stool softeners, sitz baths.

• Topical nitrates: Glyceryl trinitrate 0.2% ointment applied twice daily × 6 weeks.

• Calcium channel blockers: Diltiazem 2% cream applied twice daily.

• Botulinum toxin injection if persistent.

• Surgery (lateral internal sphincterotomy) for chronic fissure.

2. Hemorrhoids

• Conservative: fiber, sitz baths.

• Topical agents: Hydrocortisone 1% rectal cream twice daily × 7 days.

• Thrombosed external hemorrhoid: excision under local anesthesia.

• Severe hemorrhoids: rubber band ligation, surgery.

3. Perianal Abscess

• Surgical drainage is mandatory.

• Antibiotics if systemic infection:

  • Amoxicillin-clavulanate 875/125 mg orally twice daily × 7 days, OR

  • Ciprofloxacin 500 mg + Metronidazole 500 mg orally twice daily.

4. Anal Fistula

• Surgery: fistulotomy, seton placement.

• Antibiotics if active infection.

5. Proctitis

• Infectious:

  • Gonorrhea: Ceftriaxone 500 mg IM single dose.

  • Chlamydia: Doxycycline 100 mg orally twice daily × 7 days.

  • Herpes: Acyclovir 400 mg orally three times daily × 7–10 days.

• IBD-related:

  • Mesalazine suppositories 1 g rectally at bedtime.

  • Prednisolone enemas for flares.

6. Anal Cancer

• Surgery, radiotherapy, chemotherapy (based on staging).

7. Neuropathic Pain

• Amitriptyline 10–25 mg orally at night.

• Gabapentin 300 mg orally at night (titrate up to 900–1200 mg/day).

• Pelvic floor physiotherapy.

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Complications

• Chronic anal pain → impaired quality of life.

• Sepsis from untreated abscess.

• Fistula formation after abscess.

• Chronic constipation → worsening fissures/hemorrhoids.

• Missed cancer diagnosis if ignored.

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Prognosis

• Fissures/hemorrhoids: excellent with conservative or surgical treatment.

• Abscess/fistula: good after surgery, though recurrence possible.

• Cancer: prognosis depends on stage.

• Neuropathic pain: chronic but manageable.

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Patient Education

• Do not ignore anal pain — many causes are treatable, but some are serious.

• Maintain soft stools with high-fiber diet and adequate hydration.

• Avoid prolonged straining during defecation.

• Practice good anal hygiene without harsh soaps.

• Seek urgent care if:

• Severe throbbing pain with fever/swelling (possible abscess).

• Bleeding, unexplained weight loss (possible cancer).

• Sudden onset severe pain after constipation (possible fissure or thrombosed hemorrhoid).