MSFinals-4358
A mother brings her 9-month-old son Henry to the Emergency Department (ED) at 0700 h. She is very concerned. She reports that he has been crying all night. She has two older children: a 4-year-old daughter Allison and a 2-year-old son James, who are both well. Henry was born at 40+1 weeks by normal vaginal delivery. She developed gestational diabetes, but there were no other complications during the pregnancy or birth. Henry has had all his vaccinations. He was breastfed until 6 months old, then bottle-fed. Mother reports that he has been crying non-stop since 0400 h this morning. She tried to feed him, but he vomited twice, minutes after the feed. The first vomit contained food only, the second time it was greenish. Mom has not noticed a change in faeces or urine, except that she has not had to change his nappies since last night. On examination: crying, warm and well perfused, heart rate 150 beats per minute (bpm), abdomen appears distended with tinkling bowel sounds. When you look in his nappies, you notice his stools look like redcurrant jelly.
What is the most likely diagnosis?