Makindo Medical Notes

🧠 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.

🛠️ 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

• AAFP: Hirschsprung’s Disease—Diagnosis & Management
• Mayo Clinic: Hirschsprung’s Disease
• American Academy of Pediatrics