Oral Board Case: Intussusception

What is your leading diagnosis and what is your differential?

Expected answer

The classic triad of episodic colicky abdominal pain, currant-jelly stools, and a palpable sausage-shaped mass in a toddler makes ileocolic intussusception the leading diagnosis. The differential includes gastroenteritis, malrotation with volvolus, incarcerated hernia, Meckel's diverticulum, appendicitis, ovarian/testicular torsion, HSP, and constipation. Ileocolic intussusception is the most common cause of bowel obstruction in this age group (90% between 3 months and 3 years, peak 5–9 months).

What is your initial assessment and workup?

Expected answer

Assess ABCs and hemodynamic stability first. Obtain vital signs, IV access, basic labs including CBC and electrolytes, and perform a full abdominal exam looking for peritonitis. Begin resuscitation. For imaging I would obtain plain abdominal radiographs (may show signs of obstruction) followed by ultrasound, which is the diagnostic test of choice and classically shows a 'target' or 'doughnut' sign; it can also reveal a lead point or an alternative diagnosis such as appendicitis or torsion.

The ultrasound confirms ileocolic intussusception. The child is tachycardic and appears dry but has no peritonitis. What are your next steps before any reduction attempt?

Expected answer

Resuscitate before intervention: IV isotonic fluid boluses, correct electrolyte abnormalities, and consider a nasogastric tube for decompression and broad-spectrum antibiotics. Only once the child is adequately resuscitated and confirmed to have no peritonitis or perforation should I proceed to non-operative reduction with air or contrast enema. An unstable child or one with peritonitis goes directly to the OR, not to the enema suite.

Describe non-operative reduction. What are its contraindications and success rate?

Expected answer

Air (pneumatic) or contrast enema performed by an experienced radiologist reduces the intussusception in over 80% of cases and is both diagnostic and therapeutic. Contraindications are peritonitis, hemodynamic instability, or evidence of perforation. It should be done with the surgical team aware and the OR available, since perforation during enema is a recognized risk requiring emergent operation.

The enema successfully reduces the intussusception. How do you manage the patient afterward?

Expected answer

Observe for signs of recurrence and clinical deterioration. Recurrence classically was cited at 5–15%, with most occurring within the first few days and up to a third within 24 hours, though recent data suggest 24–48h recurrence under 3% after fluoroscopic air reduction. Select stable, tolerating patients may be safely discharged with clear education and follow-up. If pain recurs, repeat ultrasound; if recurrence is confirmed, repeat the enema, which can be done as often as needed provided each reduction proceeds easily and there is no peritonitis or deterioration.

Enema reduction fails after two attempts. What now, and how will you approach the operation?

Expected answer

Failed reduction is an indication for operative management. Approach—laparoscopic or open—is dictated by patient stability and surgeon preference. Open: gently reduce by pushing/milking the intussusceptum out distally while applying gentle traction proximally (traction-pulsion), avoiding forceful pulling on the intussuscepted segment. Laparoscopically a gentle traction-traction technique is used. After reduction, assess bowel viability.

Intraoperatively you reduce the bowel but it looks dusky. How do you decide on resection?

Expected answer

Assess viability after reduction—warm packs, wait, and reassess for color, peristalsis, and mesenteric pulsation. If the segment recovers, leave it. If there is frank ischemia, perforation, non-viable bowel, or the intussusception could not be reduced, resect the involved segment. If a pathologic lead point (e.g., Meckel's diverticulum, small bowel tumor, duplication cyst) is identified, resect it with primary anastomosis. Non-ileocolic small bowel–small bowel intussusception with a pathologic lead point cannot be reduced by enema and requires operative resection.

When is a small bowel–small bowel intussusception on ultrasound NOT an indication for intervention?

Expected answer

Transient small bowel–small bowel intussusception without signs of obstruction or a pathologic lead point is a common, typically self-limited incidental finding in children with abdominal pain and usually resolves spontaneously without enema or surgery. Intervention is reserved for those with obstruction, a lead point, or failure to resolve.

What features on presentation suggest advanced disease and change your urgency?

Expected answer

Fever, tachycardia, hypotension, peritonitis, lethargy, or marked pallor suggest bowel ischemia or perforation. About 15% present atypically with lethargy or pallor. These findings mandate aggressive resuscitation and direct transfer to the OR rather than attempted enema reduction.