This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
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: 
Select and explain. 
A. Pyloric stenosis, B. Duodenal atresia, C. Ileal atresia, D. Esophageal atresia
B: Duodenal atresia
Answer: B: Duodenal atresia 
Explanation: 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.