<prompt> In case of new born the commonest cause of intestinal obstruction is :Annular pancreasDuodenal AtresiaJejunal atresiaOesophageal atresia  <response>: Ans. is b ie Duodenal atresia Congenital atresia and stenosis are the commonest cause.The incidence of atresia varies with anatomical site:duodenum 35 percentjejunum 15 percentileum 25 percentascending colon 10 percentmultiple sites 15 percentVomitting is bile stained or not, depends on the atresia proximal or distal to ampulla of Vater. In 85 of cases the atresia is distal to the ampulla, therefore the vomitting is bilious.Approximately 13 of newborns with duodenal atresia have associated Downs syndrome.The double bubble seen on the air contrast upper GI series is characterstic of duodenal atresia.Treatment of choice is - Duodenoduodenostomy 