Chapter 22: Anus, Rectum, & Prostate

Anus, Rectum, & Prostate clinical guide explores the essential techniques for assessing the terminal portion of the gastrointestinal tract and the male reproductive glands, specifically focusing on the anus, rectum, and prostate. It begins with a detailed anatomical overview, distinguishing between the internal anal sphincter under involuntary control and the skeletal muscle of the external sphincter, while highlighting the significance of the pectinate or dentate line as the boundary between somatic and visceral nerve supplies. For clinicians, understanding these structures is vital for performing a digital rectal examination (DRE) that is thorough yet minimizes patient discomfort. The chapter emphasizes a systematic approach to health history, urging providers to investigate changes in bowel habits—such as stool caliber alterations or the presence of blood and mucus—alongside irritative or obstructive urinary symptoms that may indicate underlying prostatic issues. Specific attention is given to the physical examination process, detailing proper patient positioning, the inspection of the perianal area for lesions like fissures or hemorrhoids, and the systematic palpation of the rectal walls and prostate gland. In men, the guide describes identifying the lateral lobes and median sulcus of the prostate to detect abnormalities such as the "boggy" texture of acute prostatitis, the smooth enlargement of benign prostatic hyperplasia (BPH), or the hard nodules suggestive of malignancy. In women, the text notes how the uterine cervix is palpable through the anterior rectal wall, a crucial distinction during a pelvic or rectal assessment. Beyond procedural skills, the chapter delves into health promotion, particularly regarding the complexities of prostate cancer screening. It discusses the utility and controversies surrounding the prostate-specific antigen (PSA) blood test, the importance of assessing individual risk factors like age and family history, and the necessity of shared decision-making to balance the benefits of early detection against the risks of overdiagnosis and treatment complications. By integrating clinical findings, such as the American Urological Association symptom score for BPH and the identification of peritoneal metastases known as a rectal shelf, this resource prepares healthcare students and professionals to conduct sensitive, accurate, and evidence-based examinations of the anorectal and prostatic regions.