Endoscopic diagnosis of duodenal stenosis in a 5-month-old male infant.

Duodenal stenosis and duodenal atresia are well-known gastrointestinal anomalies in patients with Down syndrome. Although duodenal atresia presents early and classically with vomiting in the immediate neonatal period, the presentation of duodenal stenosis can be significantly more subtle and the diagnosis delayed. Here, we describe the case of a 5-month-old male infant with Down syndrome and delayed presentation of high-grade duodenal stenosis diagnosed endoscopically. Pediatric gastroenterologists should include duodenal stenosis in the differential diagnosis of older infants and children with vomiting and should be familiar with the endoscopic appearance of this lesion.