A 2-day-old term neonate has abdominal distension and bilious vomiting, having passed no meconium. Plain radiograph shows multiple dilated loops with a ground-glass appearance, and there are no calcifications. Family history reveals a sibling with recurrent chest infections. Which investigation is both diagnostic and potentially therapeutic?

• A Rectal suction biopsy
• B Hyperosmolar contrast (Gastrografin) enema ✓
• C Sweat chloride estimation
• D Upper gastrointestinal contrast series

Explanation

Meconium ileus results from inspissated meconium obstructing the terminal ileum in infants with cystic fibrosis, suggested here by the ground-glass (soap-bubble) appearance on plain film and the family history. A hyperosmolar contrast enema such as Gastrografin is diagnostic, showing a microcolon with pellets in the terminal ileum, and is therapeutic in up to half of cases by drawing fluid into the lumen and softening the meconium. Rectal biopsy diagnoses Hirschsprung disease, sweat chloride confirms cystic fibrosis later, and an upper GI series evaluates malrotation instead.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.