<prompt> A newborn had a bilious vomiting after 6 hours of bih. X-ray of the abdomen shows double bubble sign. This is a feature of:Pyloric stenosisDuodenal atresiaIleal atresiaEsophageal atresia  <response>: Duodenal atresia is due to failure of recanalization of the duodenal lumen during weeks 3-7 of embryologic development. Newborn will have bilious vomiting in the first 24 hours of life. Double-bubble sign and absence of gas distal to the duodenum can be seen on plain films. Ref: Wyatt C., Moos P.J., Brown T.G. 2008. Chapter 14. Gastrointestinal Pathology. In C. Wyatt, P.J. Moos, T.G. Brown Eds, Pathology: The Big Picture. 