<prompt> Answer this question truthfullyWhich cause of bilious vomiting is characterized by the obstruction of the rectosigmoid colon by meconium with a transition zone visualized on X-ray?  <response>: <reason> Hirschsprung disease is the cause of bilious vomiting that is characterized by the obstruction of the rectosigmoid colon by meconium with a transition zone visualized on X-ray. 