Examkin

Question

Difficulty: MediumPediatric Gastrointestinal Disorders

A 2-day-old full-term male newborn is evaluated in the nursery for failure to pass meconium since birth. He has developed abdominal distension and is refusing to feed. Physical examination reveals a markedly distended, tympanitic abdomen and a tight anal sphincter. A digital rectal examination results in an explosive expulsion of gas and stool.

Arrange the following steps in the most appropriate chronological order for the diagnosis and definitive management of this patient's condition.

  1. 1Obtain a plain abdominal radiograph
  2. 2Perform a water-soluble contrast enema
  3. 3Perform a rectal suction biopsy
  4. 4Perform surgical resection of the aganglionic bowel

Answer

The correct chronological sequence is: obtain a plain abdominal radiograph, perform a water-soluble contrast enema, perform a rectal suction biopsy, and finally perform surgical resection of the aganglionic bowel.
The patient's presentation of delayed meconium passage, abdominal distension, and an explosive release of stool upon digital rectal examination is classic for Hirschsprung disease. The evaluation of suspected Hirschsprung disease follows a strict, step-wise algorithm. Initially, a plain abdominal radiograph is obtained to confirm a distal bowel obstruction and rule out pneumoperitoneum. Next, a water-soluble contrast enema is performed to identify the characteristic transition zone between the narrow aganglionic segment and the dilated proximal bowel. If the enema is suggestive, the gold standard diagnostic test—a rectal suction biopsy—is performed to confirm the absence of ganglion cells. Finally, once the diagnosis is histologically confirmed, definitive treatment involves surgical resection of the aganglionic segment with a pull-through procedure.

Step-by-Step Solution

1
Obtain a plain abdominal radiograph
Identifies dilated loops of bowel and an absence of rectal gas.
This is the safest and most standard initial imaging test to confirm a mechanical bowel obstruction and rule out free intra-abdominal air before proceeding with further interventions.
2
Perform a water-soluble contrast enema
Demonstrates a transition zone between the narrow aganglionic rectum and the dilated, normally innervated proximal colon.
Helps distinguish Hirschsprung disease from meconium ileus and delineates the anatomical level of the transition zone.
3
Perform a rectal suction biopsy
Histological examination shows hypertrophied nerve trunks and a complete absence of ganglion cells.
Provides the definitive tissue diagnosis required before planning any irreversible surgical resection.
4
Perform surgical resection of the aganglionic bowel
The diseased segment is removed, and normal bowel is anastomosed to the anus.
This is the definitive curative management to restore normal bowel continuity and relieve the functional obstruction.

Key Concept

Diagnostic and management algorithm for Hirschsprung disease
Rate this question

Topics

Pediatric Gastrointestinal Disorders

More questions from this topic