Intussusception: non-operative reduction
The case
A previously well 8-month-old boy is brought to the emergency department with 6 hours of intermittent severe colicky crying, vomiting and one episode of red currant jelly stool. He is alert, with heart rate 140/min and capillary refill under 2 seconds. The abdomen is mildly distended with a palpable sausage-shaped mass in the right upper quadrant and no peritonism. Point-of-care ultrasound shows a concentric target lesion in the right lower quadrant measuring 2.5 cm, with no free fluid. Haemoglobin is 110 g/L, white cell count 9.8 × 10^9/L, electrolytes normal and CRP below 5 mg/L. What is the most appropriate next step in management?
Options
- AUltrasound-guided hydrostatic (or air) enema reduction
- BAdmit on antibiotics and await spontaneous resolution
- CCT to exclude a lead point before reduction
- DImmediate laparotomy and manual reduction
- ERigid sigmoidoscopy to visualise and reduce
Think it through before you read on. Which single option is best, and why are the other four wrong?
Show the answer and explanation
Answer
A. Ultrasound-guided hydrostatic (or air) enema reduction
Why this is the right answer
Intussusception is the commonest cause of bowel obstruction in infants between 3 months and 3 years. One segment of bowel (usually the terminal ileum) telescopes into the next (the caecum and colon). The classic triad is intermittent colicky pain with drawing up of the legs, vomiting and red currant jelly stool, although all three are present in fewer than half of cases. A sausage-shaped mass and, later, lethargy between episodes are important signs.
Ultrasound is the diagnostic test of choice, with sensitivity close to 100% in experienced hands. The 'target' or 'doughnut' sign on transverse view is diagnostic. No further imaging is needed.
In a stable child without peritonitis, perforation or shock, first-line treatment is non-operative reduction by enema under imaging guidance, either air under fluoroscopy or saline under ultrasound, performed by a radiologist with a paediatric surgeon available in case of perforation. Success is 80 to 90% for ileocolic intussusception. The Royal Children's Hospital guideline describes this pathway.
Before the procedure the child is resuscitated: intravenous access, fluids, analgesia and a nasogastric tube if vomiting. Antibiotics are given by many centres before reduction because of the small perforation risk.
Surgery is reserved for peritonitis, free air, a shocked child, or failed enema reduction. Recurrence occurs in about 10%, usually within 72 hours, so the child is observed after a successful reduction.
Why the other options are wrong
- B
Spontaneous resolution is rare and waiting risks ischaemia and perforation.
- C
CT adds radiation and is unnecessary; lead points are rare at this age and are found after failed or recurrent reduction.
- D
Laparotomy is for peritonitis, perforation or failed enema; enema reduction succeeds in most stable infants.
- E
Sigmoidoscopy cannot reach the ileocaecal region and has no role.
High-yield takeaway
Stable infant with intussusception on ultrasound: resuscitate, then image-guided air or saline enema reduction with the surgeon on standby; operate only if unstable, perforated or the enema fails.
Reference: Royal Children's Hospital Melbourne Clinical Practice Guideline: Intussusception (2020)
Common questions
What is the success rate of enema reduction?
Around 80 to 90% for ileocolic intussusception in a stable child.
When is surgery needed for intussusception?
Peritonitis, perforation or free air, a shocked child, or failure of enema reduction.
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