Chapter 10: Constipation Evaluation & Management

Constipation Evaluation & Management explores the physiological mechanisms involved in defecation, identifying key areas where interference—such as issues with the peristaltic reflex, spinal arc, or anal sphincter relaxation—can lead to motility problems. The text differentiates between acute constipation, often signaling organic causes like mechanical obstruction or adynamic ileus, and chronic constipation, which typically stems from functional disruptions in colonic storage and transport. A major focus is placed on diagnostic reasoning, emphasizing the importance of a focused patient history that evaluates stool frequency, consistency using the Bristol Stool Form Scale, and the presence of alarm symptoms or red flags such as rectal bleeding, unintended weight loss, and family history of colorectal cancer or inflammatory bowel disease. The chapter details how age impacts diagnosis, distinguishing between dietary causes in infants, withholding behaviors and encopresis in children, and malignancy risks in adults over 50. It outlines the role of lifestyle factors, including fiber intake, hydration, activity levels, and medication side effects—particularly opioid-induced constipation (OIC) and laxative dependency. The physical examination section guides practitioners through abdominal assessment for distention and masses, digital rectal examinations to check for impaction or anorectal lesions like hemorrhoids and fissures, and focused neurologic testing to rule out spinal cord issues. Furthermore, the summary covers essential diagnostic studies ranging from fecal occult blood tests (gFOBT and FIT) and complete blood counts to advanced imaging like colonoscopy, barium enemas, and anorectal manometry. Finally, the chapter provides a detailed breakdown of differential diagnoses, helping clinicians distinguish between simple or functional constipation, Irritable Bowel Syndrome (IBS), fecal impaction, Hirschsprung disease (congenital aganglionic megacolon), and secondary causes related to systemic illnesses like hypothyroidism or diabetes.