What is the step-by-step procedure for a Digital Rectal Examination (DRE)?

Digital Rectal Examination: Step-by-Step Procedure

Digital rectal examination should be performed as a standard component of lower gastrointestinal evaluation, with documentation of the examination or its omission required in 100% of cases. 1

Pre-Examination Preparation

• Explain the procedure to the patient and obtain informed consent, as patient refusal is a common barrier to performing DRE 2
• Position the patient appropriately (left lateral decubitus position is most common, though standing with hips flexed over examination table is an alternative)
• Ensure adequate lighting and have lubricant readily available
• Don gloves on both hands for the examination 3

Step-by-Step Examination Technique

Initial Inspection

• Inspect the perianal area for external hemorrhoids, fissures, skin tags, masses, or other visible abnormalities before digital insertion 3
• Note any asymmetry, inflammation, or discharge around the anal verge

Digital Insertion and Palpation

• Apply generous lubrication to the gloved index finger 3
• Gently insert the lubricated index finger into the anal canal, asking the patient to bear down slightly to relax the sphincter 3
• Assess anal sphincter tone during insertion - note whether tone is normal, increased (spasm), or decreased 3
• Palpate systematically in a circumferential manner, examining all quadrants of the rectum to a depth of approximately 7-10 cm 3

Specific Assessments

For Prostate Evaluation (in men):

• Assess prostate size - note that DRE tends to underestimate actual prostate size compared to ultrasound 4
• Evaluate symmetry of the two lobes 4
• Assess consistency - normal prostate feels rubbery, like the thenar eminence; firmness or hardness suggests pathology 4
• Detect nodules, induration, or asymmetry that may suggest prostate cancer 4
• Note that DRE should not be used as a stand-alone screening test but must be performed in conjunction with serum PSA measurement 4, 5

For Rectal Pathology:

• Palpate for masses or tumors in the lower rectum and upper anal canal - DRE is sensitive for detecting abnormalities in these areas 1
• Assess for tenderness, induration, or fluctuance that might indicate abscess or inflammatory conditions 3
• Evaluate anastomotic healing after colorectal surgery - DRE has 98.4% sensitivity for detecting anastomotic defects and yields more reliable information than water-soluble contrast enema 6
• For rectal cancer assessment, normal findings include no palpable tumor mass in the original tumor area 1

For Defecatory Disorders:

• Assess resting tone and squeeze pressure by asking patient to contract sphincter muscles 3
• Evaluate for rectocele, intussusception, or prolapse during simulated defecation maneuvers 3
• Note that DRE can yield diagnostic accuracy comparable to anorectal manometry when performed by experienced clinicians 3

Post-Examination

• Withdraw the finger gently and inspect the glove for blood, mucus, or stool character
• Document findings immediately, including whether examination was performed or omitted 1
• Inform the patient of findings and next steps

Critical Practice Points

• DRE should only be performed by healthcare workers skilled in detecting subtle abnormalities of the prostate and rectum 4
• The examination is simple and painless when performed correctly 1
• Confident performance requires dedicated training and hands-on experience with the technique 3
• For colonoscopy, DRE serves to prepare the anal canal for scope insertion and examine the anal canal and lower rectum for pathology 1
• In emergency settings, recognize that DRE can be difficult even for skilled operators to discern pathological versus normal findings, and results may have limited impact on treatment plans 7

Common Pitfalls to Avoid

• Do not rely on DRE alone for prostate cancer screening - it has poor performance in low PSA ranges with positive predictive values of only 4-11% when PSA is 0-2.9 ng/mL 5
• Do not skip the examination due to time constraints - it provides valuable clinical information that imaging may miss 6
• Do not perform the examination without adequate training - teaching should begin early in medical school using manikins, with a minimum number of supervised examinations required 2
• Recognize that interpretation can be imprecise - when in doubt, seek assistance from experienced clinicians 7