Clinical Presentation

A neonate with failure to pass meconium.

Further Work-up

(A) Abdominal radiograph demonstrates mildly gaseous, distended bowel loops throughout the abdomen (arrows) with a nondistended rectum. (B–D) Contrast enema shows a narrow, poorly distensible rectum with a transition zone (arrow).

Differential Diagnosis

• Hirschsprung disease: These findings are typical of Hirschsprung disease.

• Meconium plug: Rectosigmoid ratio should be greater than 1; small-caliber left colon; usually has multiple colonic filling defects (meconium); may pass plugs during enema.

• Meconium ileus: