Anal stricture

Almost always a complication of previous anorectal surgery

• Occurs after fibrotic replacement of the normally pliable anoderm or distal rectal mucosa
• Distinct from anal stenosis (a functional narrowing of the anal canal secondary to muscle hypertrophy or spasm)

Causative factors

• Haemorrhoidectomy - excessive anoderm excision

Presentation

• Pain with bowel movements
• Bleeding
• Difficulty evacuating
• Narrow calibre
• Incontinence
• Tenesmus
• Urgency

Examination

• Inspection: look for active disease processes
• DRE: identify location and severity of stricture

Treatment

• Treat underlying condition first - e.g. any inflammatory condition
• If the procedure was within the past month, wait for 2 months after the procedure to permit healing and resolution of inflammation
• Medical
  • Hydration
  • Fibre supplement
  • Stool softeners
  • Manual dilatation
    • Gentle insertion of well-lubricated Hegar dilators
    • Begin with size 5 in rooms, and continue up to size 18 in most patients
    • Subsequent dilatations can be done at home using a size 14 dilator (advise to avoid excessive force)
• Surgical
  • Severe strictures or those not responding to conservative management
  • Beware smokers, immunocompromised, diabetics - high risk of treatment failure, maximise conservative therapy first
  • Outcomes in crohn's/previous RTx are poor regardless
  • Malignancies - resection
  • Anastomotic/Crohns strictures - needs incision with or without stricturoplasty
  • Anoplasty: release or excision of the fibrotic strictured tissue and replacement with normal, pliable tissue with a tension-free, well-vascularised flap
  • Complications - recurrence, flap failure, UTI, haematoma, infection, abscess, chronic pain, ectropion