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Difficulty: HardPediatric Gastrointestinal Disorders

A 2-day-old full-term male neonate is evaluated in the neonatal intensive care unit for progressive abdominal distension and bilious emesis. The infant has not passed meconium since birth. Vital signs are within normal limits. Physical examination reveals a markedly distended, tympanic abdomen. Digital rectal examination produces a forceful expulsion of foul-smelling gas and stool, which temporarily relieves the distension. Arrange the following steps in the most appropriate sequential order for the diagnostic evaluation and management of this patient's most likely condition.

  1. 1Initiate intravenous fluid resuscitation and nasogastric decompression
  2. 2Obtain an anteroposterior and cross-table lateral abdominal radiograph
  3. 3Perform a water-soluble contrast enema
  4. 4Obtain a mucosal and submucosal rectal tissue sample
  5. 5Perform surgical resection of the aganglionic colonic segment

Answer

The correct sequence for managing suspected Hirschsprung disease is: initial stabilization with intravenous fluids and nasogastric decompression, followed by plain abdominal radiographs, a water-soluble contrast enema, rectal suction biopsy, and finally surgical resection.
The clinical vignette describes a classic presentation of Hirschsprung disease (delayed meconium passage, bilious emesis, abdominal distension, and a positive 'squirt sign' upon digital rectal examination). The universally accepted management protocol for neonatal distal intestinal obstruction mandates immediate stabilization (IV fluids, NGT) to prevent ischemia and aspiration. Next, a plain abdominal radiograph rules out perforation. Once deemed safe, a contrast enema provides an anatomic roadmap, looking for a transition zone. If the enema is suggestive of Hirschsprung disease, a rectal suction biopsy is performed to provide the requisite histologic confirmation. Only after ganglion cells are proven absent is the definitive surgical pull-through procedure performed.

Step-by-Step Solution

1
Initiate intravenous fluid resuscitation and nasogastric decompression
The patient's hemodynamics are supported and the risk of aspiration and further bowel dilation is minimized.
Airway, breathing, and circulation with bowel decompression take strict precedence over diagnostic testing in any neonate with bilious emesis and acute obstruction.
2
Obtain an anteroposterior and cross-table lateral abdominal radiograph
Identifies the pattern of bowel dilation (distal obstruction) and evaluates for pneumoperitoneum.
A plain radiograph is a rapid, non-invasive triage tool to confirm the need for further lower GI studies and ensure there is no perforation that would make an enema unsafe.
3
Perform a water-soluble contrast enema
Visualizes the anatomy of the lower gastrointestinal tract, often revealing a rectosigmoid transition zone characteristic of Hirschsprung disease.
This imaging study differentiates Hirschsprung disease from other causes of distal neonatal obstruction, such as meconium ileus or meconium plug syndrome.
4
Obtain a mucosal and submucosal rectal tissue sample
Provides histologic evidence demonstrating the absence of parasympathetic ganglion cells in the submucosal (Meissner) plexus.
Rectal suction biopsy is the gold-standard definitive diagnostic test and is required before any surgical intervention is undertaken.
5
Perform surgical resection of the aganglionic colonic segment
The diseased portion of the colon is removed, and normal bowel continuity is restored.
Definitive curative treatment requires excising the non-motile aganglionic segment to relieve the functional obstruction.

Key Concept

The systematic diagnostic and therapeutic approach to neonatal distal intestinal obstruction (Hirschsprung disease).
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Topics

Pediatric Gastrointestinal Disorders

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