Clinical meaning
Bowel obstruction occurs when the normal passage of intestinal contents is blocked, either mechanically (adhesions, hernias, tumors) or functionally (paralytic ileus). Proximal to the obstruction, the bowel dilates with gas and fluid, increasing intraluminal pressure, compromising blood supply, and risking perforation. Fluid sequestration in the bowel leads to dehydration and electrolyte imbalances. The nurse monitors for signs of obstruction, maintains NG tube function as directed, and reports changes.
Exam relevance
Risk factors: - Previous abdominal surgery (adhesions are #1 cause of SBO) - Hernias (incarcerated or strangulated) - Colon cancer (#1 cause of large bowel obstruction) - Crohn's disease - Diverticulitis - Volvulus - Intussusception - Fecal impaction
Diagnostics: - Monitor vital signs for signs of dehydration or shock - Auscultate bowel sounds: high-pitched tinkling (early SBO) or absent (late/ileus) - Monitor NG tube output: color, amount, and consistency - Report abdominal distension changes - Monitor I&O strictly