Small Bowel Obstruction

Key considerations: Closed-loop obstruction with strangulation, Volvulus, Internal hernia

Cannot miss

history: Prior abdominal surgeries (adhesions); Hernia history; Cancer history; IBD history; Last BM/flatus; exam: Distension; Surgical scars; Hernia orifices (inguinal, femoral, umbilical, incisional); Bowel sounds (high-pitched early, absent late); Tenderness pattern — focal = strangulation concern; labs: CBC, BMP, lactate; Lipase if epigastric pain; Type and screen; imaging: CT abdomen/pelvis with IV contrast (identifies transition point, strangulation); Abdominal X-ray: air-fluid levels, dilated loops, paucity of distal gas; bedside: POCUS for dilated loops, free fluid

immediate: NPO; NGT decompression; Aggressive IV fluid resuscitation; Correct electrolytes (hypokalemia, hyponatremia common); Foley catheter; general: Serial abdominal exams q4-6h; Follow KUB or CT if no improvement; Surgical consult early; specific: diagnosis: Partial SBO; steps: NGT decompression + bowel rest; Water-soluble contrast study (Gastrografin) at 8-24h — if contrast reaches colon by 24h, likely to resolve nonoperatively; Advance diet when improving; diagnosis: Complete SBO or Strangulation; steps: Urgent surgical exploration; Broad-spectrum antibiotics; Resection of nonviable bowel

admit: All SBO patients; Serial exams, NPO, decompression; discharge: Resolved partial SBO tolerating diet with return precautions; consults: General surgery for all SBO

CT signs of strangulation: mesenteric haziness, bowel wall thickening, reduced enhancement, free fluid, pneumatosis
Gastrografin challenge: if contrast reaches colon by 24h → 96% chance of non-operative resolution
Adhesive SBO that fails 48-72h of non-operative management → operative intervention