What is the best patient position for a digital rectal exam (DRE)?

Best Patient Position for Digital Rectal Examination

The left lateral position (lateral decubitus) with knees flexed toward the chest is the optimal position for performing a digital rectal examination (DRE). 1

Recommended Patient Positioning

• Primary Position: Left lateral (lateral decubitus) position with knees flexed toward chest 1
• Modification for Obese Patients: Have the patient raise their knee(s) up toward the chest if the prostate is incompletely felt on initial examination 2
• Alternative Position: Dorsal position (supine) may be preferred by some patients (53.9% in one study) 3

Advantages of Left Lateral Position

• Better examination of the entire circumference of the rectum (79.5% in lateral position vs 66% in dorsal position) 4
• Allows for proper assessment of:
  • Anal sphincter tone (resting and during squeeze)
  • Puborectalis muscle function
  • Perineal descent during simulated evacuation 1

Proper DRE Technique

1. Visual Inspection:

   • Separate buttocks to observe perianal area
   • Check for fecal soiling, skin lesions, and anal reflex
   • Observe perineal descent during simulated evacuation 5, 1

2. Digital Examination:

   • Assess sphincter tone at rest and during squeeze
   • Evaluate puborectalis muscle contraction
   • Check for tenderness along puborectalis (may indicate levator ani syndrome)
   • Ask patient to "expel your finger" to assess expulsionary forces 5, 1

Special Considerations

• Obese Patients: Incomplete prostate palpation strongly correlates with BMI (8.3% in normal weight vs 85.7% in extremely obese patients) 2
• Improvement Technique: Having obese patients raise their knee(s) toward their chest improves complete palpation in 95% of cases where initial examination is incomplete 2
• Patient Anxiety: Patient expectations about DRE are often negative before examination but improve significantly afterward; pain during examination is typically minimal (mean pain score of 1.69 on a 0-10 scale) 3

Documentation Requirements

• DRE performance or omission should be recorded in 100% of cases 5
• Document findings including:
  • Sphincter tone
  • Presence of masses or tenderness
  • Presence of blood
  • Prostate findings in male patients 1

Clinical Pearls

• A normal digital rectal examination does not exclude defecatory disorders 5, 1
• DRE is sensitive for detecting abnormalities in the lower rectum and upper anal canal 5
• Rectal retroflexion should be performed in 90% of cases during endoscopic procedures to complement the DRE 5

By using the left lateral position with appropriate modifications for patient body habitus, clinicians can optimize the diagnostic yield of the digital rectal examination while minimizing patient discomfort.