Overview
Why an Obstruction Becomes Dangerous
A bowel obstruction is a partial or complete interruption of intestinal flow.
REx-PN
REx-PN
A bowel obstruction is a partial or complete interruption of intestinal flow. The clinical focus is mechanical small-bowel obstruction (SBO), particularly the adhesive SBO pathway used for selected patients without evidence of ischemia or perforation. Large-bowel obstruction and functional ileus can look similar, but their causes and treatment pathways are not identical. With a mechanical obstruction, intestinal contents, swallowed air, fluid, and secretions accumulate above the blockage. The bowel wall becomes stretched and oedematous. As intraluminal pressure rises, venous drainage is impaired first; continued pressure can then reduce arterial inflow. The bowel may progress from congestion to ischemia, necrosis, perforation, and sepsis. The same process produces two immediate threats: - Vomiting and fluid sequestration in the bowel reduce circulating volume. Hypotension, acute kidney injury, and electrolyte disturbances can follow. - Distension raises the risk of bacterial translocation and perforation, especially when blood flow is compromised. This is why an apparently “constipated” patient with vomiting and progressive distension can deteriorate quickly. The obstruction is not simply a lack of stool; it is a pressure and perfusion problem. Adhesions after abdominal surgery...
Unlock full lesson + practice questions
7 more sections with scenarios, priorities, and review drills.
Final rapid review before practice
Next study step
Finish the lesson first, then choose a focused activity to apply what you just reviewed.
Continue studying
Sign in to save progress on this lesson.
Unlock the interactive lesson quiz with a plan that includes this REx-PN pathway. You can still explore topic-filtered questions from the bank hubs below.