A small bowel obstruction is a blockage that stops food, fluid and gas from moving through the small intestine. Adhesions from prior surgery are the most common cause in adults, followed by hernias and tumors, and a strangulated loop can lose its blood supply.
Key symptoms
- Crampy, wave-like abdominal pain
- Nausea and vomiting, sometimes green bile
- Bloating and abdominal distension
- No passage of stool or gas
What you find on exam
- Distended abdomen; look for surgical scars
- High-pitched or absent bowel sounds
- Hernia sites in the groin and abdominal wall
- Dehydration; fever, fast pulse or peritonitis suggest strangulation
Tests
- CT abdomen and pelvis with contrast: dilated loops and a transition point
- Abdominal X-ray: dilated loops with air-fluid levels
- Basic metabolic panel for low potassium, kidney injury and alkalosis
- Lactate and white blood cell count if ischemia is a concern
Treatment basics
- Nothing by mouth and IV fluids
- Nasogastric tube to decompress the stomach
- Correct electrolytes and track urine output
- Surgery for strangulation, closed loop, hernia or failed conservative care
Red flags
- Constant severe pain, fever or peritoneal signs
- Rising lactate, fast pulse or low blood pressure
- Incarcerated hernia that cannot be reduced
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.