Purpose or Case Report: To review the imaging appearances of neonatal bowel obstruction, focusing on the sonographic findings.
To describe the etiologies and the indication for other imaging modalities
Methods & Materials: Retrospective review of clinical, sonographic, radiological, surgical findings in neonatal obstructions.
Sonographic findings include:
- obstruction location (duodenum, small bowel, colon)
- bowel size (location, amount and size of dilated loops, presence or not of a microcolon)
- bowel content (anechoic fluid, hyperechoic plugged meconium, normal hypoechoic meconium)
- others: location of mesenteric vessels, presence of a cyst.
Results: 1. US features of normal neonatal bowel
2. US in Upper GI tract obstruction:
Etiologies: duodenal atresia or diaphragm; malrotation with midgut volvulus; duodenal duplication cyst
Management: immediate surgery or upper GI tract opacification
3. US in Lower GI tract obstruction:
- Small bowel dilatation with microcolon:
Etiologies: small bowel atresia, meconium ileus, meconium obstruction in extremely-low-birth-weight premature infant, meconial pseudocyst, total colonic Hirschsprung's disease
Management: low or high osmolality iodine enema
- Small bowel dilatation without microcolon:
Etiologies: Hirschsprung's disease, meconium plug syndrome, small left-colon syndrome, rectal or colon atresia, small bowel duplication cyst, intussusception
Management: iodine enema or immediate surgery

Conclusions: US is a valuable examination in the assessment of neonatal bowel obstruction. It can identify the location and the cause of the obstruction, allowing the appropriate management: upper GI tract series, low or high osmolality iodine enema, surgery.