Anoscopy

Overview

• The use of an anoscope to visually inspect the anus, anal canal, and internal sphincter
• Helpful in identifying causes of rectal bleeding
  • Up to 50% of rectal bleeding is falsely attributed to hemorrhoids when internal examination is not used

Indications

• Evaluation of bright red bleeding
• Evaluation anorectal symptoms (anal pain, discharge, protrusions, or pruritus)
• Evaluation/treatment of rectal foreign bodies

Contraindications

Absolute Contraindications

• Imperforate anus
• Bowel Perforation
• Significant active bleeding

Relative Contraindications

• Severe anal pain
• Recent anal surgery

Equipment Needed

• Gloves
• Anoscope (Reusable or disposable)
  • Adults: 7-cm (typically 19-mm diameter) anoscope; slotted or non-slotted
  • Pediatrics: 8-mm to 14-mm diameter
• Light source (often built into disposable anoscopes)
• Lubricating jelly (and topical anesthetic jelly if patient has severe anal pain)
• Cotton swabs
• If needed:
  • Fecal occult blood test
  • Culture tube and swab
  • Biopsy forceps

Procedure

• Position the patient (lithotomy position or left lateral decubitus w/ knees flexed toward chest)
• Pull buttock apart, inspect the external area
• Perform digital rectal exam with lubricated, gloved finger (use topical anesthetic jelly if needed and wait 1-2 minutes prior to anoscopy)
• Lubricate the anoscope and the central guide plug (obturator)
• Slowly insert the anoscope fully, maintaining pressure on the obturator.
  • If obturator slips or falls out during insertion, remove anoscope completely and repeat procedure
• Once inserted, remove the obturator (keep it nearby if needed again)
• Slowly withdraw, rotate (if non-slotted anoscope), and visual the entire circumference of the canal
• Perform any biopsies (if above dentate line) or cultures as needed

Complications

• Tearing of perianal skin/mucosa
• Abrasion or tearing of hemorrhoidal tissue
• Infection (rare)