Surgery MCQs Q45

FreeMedSite

PAEDIATRIC SURGERY • GI

A 2-month-old boy presents with chronic constipation, straining during defecation, abdominal distension, and failure to thrive. A rectal examination followed by biopsy is performed.

Which of the following statements regarding this condition is true?

A Best diagnosed in the newborn period by barium enema

B Initially treated by colostomy

C Characterized by absence of genitourinary anomalies

D Associated with high incidence of genitourinary anomalies

E Most commonly leads to subsequent fecal incontinence

The correct answer is Associated with high incidence of genitourinary anomalies.

Decoding the Stem

1

CLUE "Infant + constipation + distension + biopsy"

TRANSLATION Hirschsprung’s disease (congenital aganglionic megacolon).

Detailed Explanation

✅ Correct Option (Associated Anomalies): Hirschsprung’s disease results from the failure of neural crest cell migration, leaving the distal colon aganglionic. It is frequently associated with other congenital conditions, including Down syndrome and a high incidence of genitourinary anomalies (e.g., hydronephrosis, renal agenesis).

❌ Why other options are incorrect:

→ Barium enema: While helpful for identifying a "transition zone," it is not the gold standard. Rectal suction biopsy is required for a definitive diagnosis.

→ Initially treated by colostomy: Modern management often favors a primary pull-through procedure. Colostomy is only utilized if the child is severely ill or has significant enterocolitis.

→ Fecal Incontinence: The hallmark of this disease is constipation and functional obstruction; incontinence is not the primary clinical concern.

🧠 High-Yield Pearls

✔ Pathophysiology: Absence of Auerbach and Meissner plexuses.

✔ Gold Standard: Full-thickness or suction rectal biopsy showing absent ganglion cells and hypertrophied nerve trunks.

✔ Symptoms: Delayed meconium passage (>48 hrs) is a classic early clue.

Integrated Clinical Questions

1. Most common site affected?

→ The rectosigmoid region (most distal part).

2. Pathophysiology?

→ Failure of neural crest cell migration in a craniocaudal direction.

3. Radiological sign?

→ Transition zone (narrow aganglionic distal segment with proximal dilation).

4. Major complication?

→ Enterocolitis (Hirschsprung-associated enterocolitis), which is potentially life-threatening.

5. Definitive treatment?

→ Surgical resection of the aganglionic segment followed by a pull-through procedure (e.g., Duhamel, Soave, or Swenson).

⚡ Exam Pearls

• • Biopsy = confirmatory test (gold standard).
• • Always think: Infant + constipation + distension = Hirschsprung.
• • Associated with Down syndrome and GU anomalies.
• • Functional obstruction is caused by the lack of relaxation in the aganglionic segment.

← Previous Question Next Question →

FreeMedSite • Open Medical Education