🧠 Hirschsprung's disease is a congenital absence of enteric ganglion cells in the distal bowel → tonic contraction and functional obstruction. Early recognition and surgery prevent life-threatening enterocolitis and support normal growth. 👶

📖 About

Hirschsprung's disease = aganglionosis of the distal bowel (myenteric + submucosal plexuses) → failure of relaxation 🚫.
Also called congenital megacolon; incidence ≈ 1:5,000 live births.

🤝 Associations

Family history 👪
Genetic: Down syndrome (Trisomy 21), Waardenburg, MEN2 (RET), neurofibromatosis 🧬
Other anomalies: VSD, renal anomalies 🫀🟦

🧪 Pathology

Failed neural crest migration → absent parasympathetic ganglion cells distally.
Aganglionic segment remains narrowed; proximal bowel becomes dilated and hypertrophic → megacolon 📈.

📍 Extent (Aetiology)

~70% rectosigmoid (short-segment) ✅
~20% entire colon (long-segment) ⚠️
~10% may extend into small intestine (total colonic/ileal) ⚠️

🩺 Clinical Features

🍼 Neonate: Delayed meconium >48 h, abdominal distension, bilious vomiting, poor feeding.
👶 Infant/child: Chronic constipation, abdominal bloating, FTT; explosive stool after DRE (“squirt sign”).
🔥 Hirschsprung-associated enterocolitis (HAEC): Fever, severe distension, foul diarrhoea, lethargy → emergency.

🔍 Differential Diagnoses

Functional constipation
Meconium ileus (CF) 🧪
Imperforate anus / anorectal malformation
Neonatal sepsis, intestinal atresia

🧪 Investigations (corrected)

🩻 Abdominal X-ray: Distended bowel loops; paucity of rectal gas.
🧪 Contrast enema: Transition zone (narrow distal aganglionic segment with proximal dilatation); avoid rectal exam just before study.
🎯 Anorectal manometry (infants): Absent recto-anal inhibitory reflex (RAIR) ➖.
🔬 Suction rectal biopsy (gold standard): Absent ganglion cells + hypertrophic nerve trunks; do ≥1.5 cm above dentate line.
🧬 Consider genetic testing (RET) and screen for associated anomalies; newborn CF screen if meconium ileus suspected.

💡 OSCE/Exam Pearl: Delayed meconium + distension + “squirt sign” after DRE → think Hirschsprung’s. Diagnosis is by rectal suction biopsy, not by contrast enema alone.

🛠️ Management

⛑️ Stabilise: IV fluids, NG decompression, broad-spectrum antibiotics if HAEC, rectal saline washouts 💧.
🔪 Definitive surgery (pull-through):
- Swenson: Resection of aganglionic rectum with coloanal anastomosis.
- Soave: Endorectal mucosectomy; pull-through within muscular cuff.
- Duhamel: Side-to-side retrorectal anastomosis forming a neorectum.
🧷 Stoma: Considered in enterocolitis, severe dilatation, or staged procedures.
🏥 Post-op: Monitor for HAEC, anastomotic leak/stricture; bowel regimen, pelvic floor support.

📚 Case Example

👶 Case: Term male, day-3 of life, has not passed meconium. Marked distension, bilious vomiting, and a gush of foul stool after DRE (“squirt sign”). 🩻 AXR: Dilated bowel loops, paucity of rectal gas. 🧪 Contrast enema: Rectosigmoid transition zone. 🔬 Suction rectal biopsy: Absent ganglion cells with hypertrophic nerves → Hirschsprung’s confirmed. 🛠️ Management: IV fluids, rectal washouts, then laparoscopic-assisted Soave pull-through. ✅ Outcome: Good weight gain; stooling programme and surveillance for HAEC/stricture.

🔭 Prognosis

👍 Generally favourable after pull-through.
♻️ Some children have persistent constipation, soiling, or enterocolitis episodes—needs long-term follow-up.

🔗 References

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Hirschsprung disease (congenital megacolon)