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[1]

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
Use of anoscope for internal inspection of the lower rectum

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)[2]

See Also

External Links

Videos

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References

  1. Gudur A, Shanmuganandamurthy D, Szep Z, Poggio JL. An Update on the Current Role of High Resolution Anoscopy in Patients With Anal Dysplasia. Anticancer Res. 2019 Jan;39(1):17-23.
  2. London S, Hoilat GJ, Tichauer MB. Anoscopy. [Updated 2021 Jun 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459324/