OnExam

The digital rectal exam is used to examine the palpable prostate, rectum, anus, and to assess for spinal cord injury, foreign bodies, and bloody stool.

Performing the Test

  1. For a right-handed examiner, ask the patient to lie on their left side, buttocks close to edge of table, with hips and knees flexed
  2. Lubricate gloved, right index finger
  3. Ask patient to strain down, place pad of index finger over anus
  4. Warn the patient that you are about to touch them and it's likely to feel cold from the lubricant
  5. Once sphincter relaxes, insert index fingertip into anal canal in direction facing umbilicus. Ensure that the remainder of your fingers are flexed into your palm. Assess:
    • Tone of sphincter and anus
    • Tightness may indicated anxiety, inflammation, scarring
    • Laxity is associated with some neurologic diseases
    • Nodules, irregularities, induration, tenderness
  6. After inserting finger into rectum as far as possible:
    • Palpate posterior wall of rectum
    • Rotate hand clockwise to palpate right side of rectum
    • Rotate hand counterclockwise to palpate left side of rectum
    • To bring suspected lesion into reach, take finger off rectal surface, ask patient to strain down, palpate again
  7. Rotate hand counterclockwise so that finger examines posterior surface of prostate gland and note:
    • Identify lateral lobes and median sulcus
    • Size, shape, consistency
    • A normal prostate is rubbery, nontender, ~2.5 cm long
  8. Extend finger beyond prostate to region of seminal vesicles/peritoneal cavity
    • Palpate rectal shelf for peritoneal metastases (Blumer's shelf) or tenderness (peritoneal inflammation)
  9. Withdraw finger
    • Note colour fo fecal matter on glove finger
    • Test for occult blood
  10. Give the patient a tissue to clean up with

Interpretation

  • For assessing spinal cord injuries in patients who underwent blunt trauma, the DRE is insensitive (only 50%) but reasonably specific (93%). It's positive predictive value is only 27%.

References

  1. Bickley, S. L. The Anus, Rectum, and Prostate. In: Bates’ Guide to Physical Examination. 10th ed. Philadelphia PA: Lippincott Williams & Wilkins; 2009: 555-564.
  2. Guldner, GT. The sensitivity and specificity of the digital rectal examination for detecting spinal cord injury in adult patients with blunt trauma. Am J Emerg Med. 2006. Jan;24(1):113-7.