Chapter 26: Anus, Rectum, and Prostate

Anus, Rectum, and Prostate delivers a comprehensive overview of the anatomical structures, physiological functions, and detailed physical assessment techniques for the anus, rectum, and prostate gland. It establishes a foundational understanding of the lower gastrointestinal and male reproductive anatomy, detailing the mechanisms of the internal and external sphincters, the rectal ampulla, and the prostate's glandular components, including the seminal vesicles and bulbourethral glands. The text systematically guides the clinician through the collection of subjective health history, focusing on evaluating bowel routines, identifying abnormalities like melena or steatorrhea, and recognizing symptoms of underlying rectal conditions such as dyschezia and fecal incontinence. For the objective examination, it outlines the precise methodological steps for conducting perianal inspections and digital rectal examinations across various patient positions, emphasizing the evaluation of sphincter tone, mucosal integrity, and prostate characteristics like size, shape, and nodularity. The chapter incorporates critical developmental competence, contrasting pediatric assessments—such as monitoring the gastrocolic reflex and infant meconium passage—with geriatric considerations like the high prevalence of benign prostatic hyperplasia and decreased sphincter control. Significant clinical focus is directed toward health promotion, disease prevention, and the impacts of genetic and environmental disparities, offering evidence-based guidelines on prostate-specific antigen (PSA) screening for prostate cancer and fecal immunochemical tests (FIT) alongside colonoscopies for colorectal cancer detection. Finally, it equips healthcare professionals with the diagnostic criteria to identify and document a wide array of pathological abnormalities, ranging from common benign issues like thrombosed hemorrhoids, anal fissures, and pilonidal cysts to severe complications such as anorectal fistulas, fecal impaction, prostatitis, and malignant colorectal and prostatic neoplasms.