Hirschsprung disease vs Meconium ileus
How to tell Hirschsprung disease and Meconium ileus apart when a board question makes them look alike.
Step 2 CK pairs are in open beta while clinical review finishes. Spot an issue? Tell us.
Rectal suction biopsy showing absent ganglion cells confirms Hirschsprung disease.
Side by side
Failure to pass meconium with abdominal distension and explosive stool after rectal exam due to distal aganglionosis.
Neonatal distal bowel obstruction from inspissated meconium, strongly associated with cystic fibrosis.
Absent enteric ganglion cells in distal colon prevent relaxation and cause functional obstruction.
Abnormally thick intestinal secretions in cystic fibrosis obstruct the terminal ileum with dense meconium.
Contrast enema often shows a narrow distal segment with proximal dilation, anorectal manometry shows absent rectoanal inhibitory reflex, and definitive diagnosis is rectal suction biopsy showing absent ganglion cells.
Contrast enema often shows a microcolon with inspissated pellets in distal ileum, and confirmatory workup includes positive cystic fibrosis testing such as elevated sweat chloride at or above 60 mmol/L.
The trap
Both disorders present with delayed meconium passage and distension, so clinicians may stop after initial decompression. The resolving clue is anatomic level and confirmation test: microcolon on contrast enema points to meconium ileus with cystic fibrosis evaluation, while aganglionosis requires biopsy confirmation and definitive pull-through surgery planning.
The repair move
Next best step: decompress bowel with rectal irrigation and supportive fluids, then confirm Hirschsprung disease with rectal suction biopsy and arrange definitive pull-through surgery. If contrast enema shows microcolon with meconium pellets, treat meconium ileus with hyperosmolar enema under fluoroscopy and evaluate for cystic fibrosis with sweat chloride testing and genetics.
Try a free question
CoreA full-term newborn has not passed meconium by 48 hours and has abdominal distension. BP 70/42 mm Hg, HR 160/min, temp 36.9 C. Rectal exam causes explosive stool release. What is the next best step in management?
Show answer and explanation
Answer: B. Rectal suction biopsy evaluation for Hirschsprung disease after stabilization. Delayed meconium with explosive stool after rectal exam strongly suggests Hirschsprung disease and requires confirmatory biopsy.
Why the other choices are tempting
- A. Wrong. Neonatal obstruction signs need urgent evaluation, not discharge.
- C. Wrong. Oral laxatives do not address congenital obstructive pathology.
- D. Wrong. Pyloric stenosis causes nonbilious vomiting later in infancy and does not explain delayed meconium.
- E. Wrong. Ongoing obstruction without workup can progress to enterocolitis and perforation.
Flashcards
Tap a card to flip it.
Which definitive test confirms Hirschsprung disease?
Rectal suction biopsy showing absent ganglion cells confirms Hirschsprung disease.
What contrast enema pattern favors meconium ileus?
A microcolon with inspissated meconium in distal ileum favors meconium ileus.
Quick answers
What is the fastest way to tell Hirschsprung disease from Meconium ileus?
Rectal suction biopsy showing absent ganglion cells confirms Hirschsprung disease.
What is the key clue for Hirschsprung disease?
Failure to pass meconium with abdominal distension and explosive stool after rectal exam due to distal aganglionosis.
What is the key clue for Meconium ileus?
Neonatal distal bowel obstruction from inspissated meconium, strongly associated with cystic fibrosis.
What is the common trap with Hirschsprung disease vs Meconium ileus?
Both disorders present with delayed meconium passage and distension, so clinicians may stop after initial decompression. The resolving clue is anatomic level and confirmation test: microcolon on contrast enema points to meconium ileus with cystic fibrosis evaluation, while aganglionosis requires biopsy confirmation and definitive pull-through surgery planning.