What is the proper technique for performing a Digital Rectal Examination (DRE)?

Digital Rectal Examination Technique

Digital rectal examination should be performed with the patient in the left lateral (Sims) position, as this allows the most thorough examination of the entire rectal circumference, though the dorsal lithotomy position is also acceptable with slightly reduced circumferential assessment. 1

Patient Positioning

• Position the patient in the left lateral decubitus position with knees drawn toward the chest, as this enables examination of 79.5% of the rectal circumference compared to only 66% in the dorsal position. 1
• Alternative positions include modified lithotomy (preferred by 63.4% of urologists), standing with elbows on table, or dorsal lithotomy, though these may limit complete examination. 2, 1
• The standing position offers faster examination time but no difference in diagnostic accuracy for prostate assessment. 2

Pre-Examination Steps

• Obtain informed consent and explain the procedure to reduce patient anxiety. 3
• Ensure adequate lighting and have the patient empty their bladder if evaluating for urinary retention. 4
• Wear gloves and use adequate water-based lubricant on the examining finger. 3

Inspection Phase

• Separate the buttocks and observe the perianal area for fecal soiling, skin excoriation, hemorrhoids, fissures, or fistulas. 5
• Observe perineal descent during simulated defecation (ask patient to "bear down as if having a bowel movement") - normal descent is 1-3 cm; excessive descent (>3 cm) suggests pelvic floor dysfunction. 5
• Check for anal patulous opening during straining, which may indicate neurogenic dysfunction, or observe for mucosal prolapse. 5
• Test the anal reflex by light scratch or pinprick of perianal skin - absence suggests neurologic pathology. 5

Digital Palpation Technique

• Gently insert the lubricated index finger through the anal canal, directing posteriorly initially to follow the natural curve of the rectum. 3
• Assess resting anal sphincter tone immediately upon insertion - note if tone is normal, increased (spastic), or decreased (hypotonic). 5, 3
• Evaluate squeeze pressure by asking the patient to "squeeze as if holding back stool" - assess the strength and duration of contraction of both internal sphincter and puborectalis muscle. 5, 3
• Palpate the puborectalis muscle posteriorly - acute tenderness suggests levator ani syndrome. 5

Systematic Rectal Examination

• Sweep the finger circumferentially to examine all quadrants of the rectal wall (anterior, posterior, and both lateral walls) up to the examining finger's length (approximately 8-10 cm). 5, 1
• Palpate for masses, polyps, strictures, or areas of induration - DRE is sensitive for detecting abnormalities in the lower rectum and upper anal canal. 5
• In women, assess the anterior rectal wall for rectocele by having the patient bear down while your finger is in the rectum. 5

Prostate Examination (in Men)

• Palpate the prostate anteriorly through the anterior rectal wall, assessing size, symmetry of both lobes, consistency, and presence of nodules or induration. 6, 4
• Evaluate for asymmetry, firmness, or nodularity that may suggest prostate cancer - DRE should be performed by clinicians skilled in detecting subtle abnormalities. 6
• Note that DRE tends to underestimate prostate size; if the prostate feels large on DRE, it is usually significantly enlarged on ultrasound. 6
• DRE should not be used as a stand-alone screening test but should be combined with PSA measurement for prostate cancer screening. 6

Assessment of Defecatory Function

• Instruct the patient to "push out my finger as if having a bowel movement" to assess the coordination of defecatory effort. 5, 3
• Normal response includes relaxation of the puborectalis and external sphincter with increased intra-abdominal pressure. 3
• Paradoxical contraction (tightening instead of relaxing) during simulated defecation suggests dyssynergic defecation or pelvic floor dysfunction. 3

Post-Examination

• Withdraw the finger gently and inspect the glove for stool color, consistency, blood, mucus, or melena. 3
• Provide the patient with tissues to clean themselves and allow them to dress in privacy. 7
• Document findings systematically: sphincter tone, masses, tenderness, prostate characteristics (if applicable), stool characteristics, and any abnormalities detected. 5

Quality Standards for Colonoscopy Context

• When DRE is performed as part of colonoscopy preparation, it should be recorded in 100% of cases whether performed or omitted. 5
• DRE serves dual purposes: preparing the anal canal for scope insertion and examining for pathology that may be missed by endoscopy alone. 5

Clinical Contexts Requiring DRE

• Constipation evaluation: DRE can yield diagnostic accuracy comparable to anorectal manometry for identifying defecatory disorders. 3
• Rectal cancer screening: DRE remains important for detecting early-onset rectal malignancies, particularly in patients with red-flag symptoms like rectal bleeding. 8
• Prostate assessment: Begin at age 50 for average-risk men, age 45 for African Americans or those with family history. 5, 6
• Pre-colonoscopy assessment: Recommended as standard practice before lower GI endoscopy. 5

Common Pitfalls to Avoid

• Inadequate lubrication causes patient discomfort and limits examination quality. 3
• Rushing the examination without systematic circumferential palpation misses lateral and posterior wall lesions. 1
• Failing to assess defecatory function in patients with constipation leads to missed diagnoses of pelvic floor dysfunction. 5, 3
• Using DRE alone for prostate cancer screening without PSA measurement reduces sensitivity. 6
• Not documenting whether DRE was performed or omitted fails quality standards for colonoscopy. 5