A 15-month-old previously healthy boy presents to the emergency department with sudden onset of severe, intermittent abdominal pain. His parents report that he has been crying inconsolably during these episodes, which last for several minutes before he seems to calm down temporarily. They also noticed that he has been drawing his knees up to his chest during the painful episodes. Over the past day, he has had two episodes of vomiting and passed a stool that looked like "red jelly."

On examination, the boy appears pale and lethargic between episodes of pain. His abdomen is tender, and a sausage-shaped mass is palpable in the right upper quadrant. An abdominal ultrasound confirms the diagnosis of intussusception, showing a characteristic "target sign."

The patient is immediately referred for treatment, where a non-surgical air enema reduction is performed successfully to resolve the intussusception.