MSFinals-4357

A 9-month-old infant is presented to the emergency department by his parents due to several hours of profuse vomiting. The vomit is thick and green in colour, and the infant has not had any wet nappies in the past 24 hours. Upon examination, the infant appears distressed and is crying. An abdominal examination reveals a distended abdomen and absent bowel sounds. The infant has no significant medical history, and the pregnancy and delivery were uneventful. What is the most probable diagnosis?