Newborn with failure to pass meconium

Barium enema of uncomplicated meconium ileus
Early (left) image from a water-soluble contrast enema shows a microcolon and reflux of contrast into a non-dilated terminal ileum. Later (right) image from the same enema shows reflux of contrast into dilated loops of ileum, which are above the level of the obstruction by meconium in the terminal ileum.

The diagnosis was uncomplicated meconium ileus.