Chapter 135: Meconium Ileus, Peritonitis, Intestinal Obstruction, and Gastroschisis

Meconium plug syndrome · Meconium ileus (CF association) · Meconium peritonitis · Gastroschisis · Intestinal atresia · Contrast enema · Surgical management
🩺 Key fact: 90% of newborns pass meconium within 24h. Failure to pass by 24-36h → suspect obstruction.

🩺 Neonatal Intestinal Obstruction: Core Concepts

📦 Meconium plug syndrome
Obstruction of distal colon/rectum by meconium. Associated with CF (40%), Hirschsprung (40%), maternal MgSO4/opiates. Contrast enema diagnostic & therapeutic.
🧬 Meconium ileus
Inspissated meconium in distal ileum. 30% of neonatal obstructions. Highly associated with CF (CFTR mutations). Microcolon on enema. Gastrografin enema or surgery.
⚡ Meconium peritonitis
In utero intestinal perforation → sterile chemical peritonitis, calcifications, ascites. Can present with hydrops. Caused by meconium ileus, atresia, volvulus.
🫀 Gastroschisis
Abdominal wall defect lateral to umbilicus, no sac. Intestines exposed. Associated with young maternal age. High risk of intestinal atresia, short bowel syndrome.
📊 Abdominal wall defect comparison
Gastroschisis: no sac, right of umbilicus, bowel exposed. Omphalocele: sac, central, may contain liver, higher associated anomalies.
🔬 Associated conditions
CF (meconium ileus), Hirschsprung (meconium plug), trisomies (omphalocele), Beckwith-Wiedemann (omphalocele).
⚠️ Warning signs: Bilious vomiting, abdominal distention, failure to pass meconium by 24-36h, calcifications on X-ray (meconium peritonitis).

🔍 Approach to newborn with suspected intestinal obstruction

1
History & exam – Bilious vomiting, abdominal distention, failure to pass meconium by 24-36h. Family history of CF or Hirschsprung.
2
Plain abdominal X-ray – Dilated bowel loops, air-fluid levels. Microcolon suggests meconium ileus. Calcifications indicate meconium peritonitis.
3
Contrast enema (Gastrografin or dilute barium) – Diagnostic and often therapeutic for meconium plug/ileus. Shows microcolon in meconium ileus.
4
Consider CF and Hirschsprung – Sweat test (CF) and rectal suction biopsy (Hirschsprung) after resolution of obstruction.
5
Gastroschisis/omphalocele – Prenatal diagnosis. Delivery at tertiary center. Cover exposed bowel, NG decompression, surgical repair.

📋 Stepwise management of neonatal intestinal obstruction

1
Stabilization – NPO, nasogastric decompression, IV fluids, correct electrolytes. Broad-spectrum antibiotics if peritonitis suspected.
2
Meconium plug: contrast enema (Gastrografin) – Hyperosmolar solution draws fluid into bowel, loosens plug. Monitor for fluid shifts. Usually curative.
3
Meconium ileus: Gastrografin enema – If unsuccessful or complicated (atresia, volvulus, perforation) → surgery: enterotomy with irrigation, resection with stoma.
4
Meconium peritonitis – Supportive care, abdominal drainage, surgical intervention for persistent obstruction or perforation.
5
Gastroschisis – Cover exposed bowel with sterile plastic bag, NG tube, IV fluids, antibiotics. Surgical reduction (primary or staged with silo).
📌 Gastrografin caution: Hyperosmolar (1900 mOsm/L). Dilute 1:1 with water, give IV fluids during and after to prevent dehydration/shock.

🧠 Rapid reflex prompts – Meconium & obstruction

📌 Meconium ileus is strongly associated with?
Cystic fibrosis (CF) – 80-90% of cases.
📌 First test for meconium plug?
Gastrografin enema (diagnostic + therapeutic).
📌 X-ray finding in meconium peritonitis?
Intra-abdominal speckled calcifications (from in utero perforation).
📌 Gastroschisis vs omphalocele?
Gastroschisis: no sac, right side, bowel only. Omphalocele: sac, central, may contain liver.
📌 Meconium plug associated with (2 conditions)?
Hirschsprung disease (40%) and CF (40%).
📌 Most common life-threatening complication of gastroschisis?
Intestinal atresia/necrosis → short bowel syndrome.
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