Clinical meaning
Bowel obstruction requires the clinician to differentiate mechanical from functional causes, identify the level and completeness of obstruction, and determine operative vs. non-operative management. In mechanical SBO, adhesive obstruction (60%) can often be managed conservatively with NG decompression and volume resuscitation, while strangulated, closed-loop, or complete obstructions require emergent surgery. In LBO, malignancy must be excluded. Functional ileus is managed by treating the underlying cause (electrolyte correction, medication adjustment, sepsis control). The clinician must interpret imaging, order appropriate labs, prescribe fluid and electrolyte replacement, and determine surgical consultation timing.
Diagnosis & workup
Diagnostics & workup: - Order CT abdomen/pelvis with IV contrast (gold standard): identifies transition point, closed-loop, strangulation, free air - Order upright and supine abdominal X-ray: air-fluid levels, dilated loops (>3cm small bowel, >6cm colon, >9cm cecum) - Order CBC: leukocytosis suggests strangulation; anemia may suggest malignancy - Order CMP: metabolic alkalosis from vomiting, hypokalemia, elevated BUN (dehydration), pre-renal AKI - Order serum lactate: elevated suggests bowel ischemia - Order blood type and screen if surgery anticipated - Order colonoscopy/sigmoidoscopy for LBO to rule out malignancy and attempt decompression