A newborn fails to pass meconium within the first 24 to 48 hours after birth. On rectal examination, the infant passes stool and flatus. This clinical presentation should raise suspicion of which congenital condition?

1. A

   Intussusception

2. B

   Hirschsprung's disease

3. C

   Pyloric stenosis

4. D

   Meconium ileus

Appeared in: NORCERT 8 Mains-2025

Explanation

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• The failure of a newborn to pass meconium within the first 24-48 hours is a cardinal sign of neonatal intestinal obstruction, with Hirschsprung's disease being a primary cause.
• The underlying pathology is the absence of ganglion cells (aganglionosis) in the distal colon, which prevents the bowel from relaxing and leads to a functional obstruction.
• The explosive passage of stool and flatus after a digital rectal exam (known as the 'squirt sign' or 'blast sign') is a classic finding, as the exam temporarily opens the constricted aganglionic segment.

Why Other Options Were Wrong

• Option A: This condition typically presents in older infants (3-36 months) with sudden colicky pain and 'currant jelly' stools, not a failure to pass meconium at birth.
• Option C: This condition involves the stomach outlet, causing projectile non-bilious vomiting at 2-8 weeks of age. It does not affect the initial passage of meconium.
• Option D: While it causes failure to pass meconium, the obstruction is from thick, sticky meconium (linked to cystic fibrosis). A rectal exam reveals a narrow, empty rectum (microcolon), not an explosive passage of stool.

Related Visual

• Visual 1: Diagram: Pathophysiology of Hirschsprung's disease, showing the narrowed aganglionic segment and the dilated, healthy proximal bowel.
• Visual 2: Image: Barium enema of an infant with Hirschsprung's disease, highlighting the 'transition zone' between the narrow distal segment and the dilated proximal colon.
• Visual 3: Illustration: The 'squirt sign' during a rectal examination, depicting the forceful expulsion of stool and gas.

Clinical Relevance

• Nursing practice connection: Safe nursing care depends on performing Differential diagnosis of neonatal intestinal obstruction in the correct sequence, documenting the action clearly, and monitoring for the expected response.
• Early recognition of Hirschsprung's disease is critical to prevent Hirschsprung-Associated Enterocolitis (HAEC), a life-threatening complication involving fever, abdominal distension, and foul-smelling diarrhea.
• Nurses play a vital role in the initial assessment of newborns, and their prompt identification of delayed meconium passage is key to timely diagnosis and management.
• What if? If the infant passed meconium normally but later, in the first few months, developed chronic constipation, abdominal distension, and ribbon-like stools, Hirschsprung's disease would still be a strong possibility, as the presentation can be less acute.

How to Approach the Question

• First, identify the key clinical findings from the question: a newborn, failure to pass meconium within the standard 24-48 hour window, and a specific reaction to a rectal exam.
• Recognize that delayed meconium passage is a major red flag for a lower intestinal obstruction in a neonate.
• Focus on the most specific and unique clue: the explosive passage of stool and gas immediately following the rectal exam. This points to a functional obstruction that was temporarily relieved by mechanical dilation.
• Evaluate the options based on this specific clinical picture. Hirschsprung's disease, caused by a non-relaxing (aganglionic) segment of the colon, perfectly explains this 'squirt sign'.
• Systematically rule out the other options by recalling their classic presentations: Intussusception (older infant, 'currant jelly' stool), Pyloric Stenosis (projectile vomiting, stomach issue), and Meconium Ileus (thick meconium, empty microcolon on exam).

Concept Tested & Keywords

• Concept Tested: Differential diagnosis of neonatal intestinal obstruction
• Stem keywords: newborn, fails to pass meconium, 24 to 48 hours, rectal examination, passes stool and flatus
• Lead-in keywords: suspicion of which congenital condition
• Clinical cues: The combination of delayed meconium passage and the 'squirt sign' on rectal exam is a pathognomonic clue for Hirschsprung's disease.
• Negative lead-in flag: false

Question ID

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