Clinical meaning
The digital rectal examination (DRE) provides critical clinical information about the anal canal, rectum, and prostate (in males). Technique: patient in left lateral decubitus or standing bent forward, inspect perianal area first (skin tags, hemorrhoids, fissures, fistula openings, condylomata, masses, perianal dermatitis), then gently insert lubricated gloved index finger through the anal sphincter assessing sphincter tone (normal, decreased, increased), and systematically palpate the rectal mucosa circumferentially for masses, tenderness, or irregularities. In males, the prostate is palpated anteriorly through the rectal wall: assess size (normal 3-4 cm transverse, approximately 20-25 g), consistency (normal = firm and rubbery like thenar eminence), symmetry, surface contour (smooth vs nodular), median sulcus (normally palpable groove between lateral lobes), tenderness, and mobility. Prostate findings: benign prostatic hyperplasia = symmetrically enlarged, smooth, firm, non-tender; prostatitis = tender, boggy, warm; prostate cancer = hard nodule(s), asymmetry, obliterated median sulcus, fixed to surrounding tissue. Stool on the examining finger should be tested for occult blood if clinically indicated.