A 7-month-old child presented to the emergency department (ED) with 2 hours of painless, nonprojectile emesis and a normal mental status. Over a 3-hour period in the ED, the child remained pain-free, but developed hematemesis, hematochezia, and lethargy, progressing to unresponsiveness. The patient was evaluated for toxic ingestion, intracranial bleed, sepsis/meningitis, and intraabdominal pathology. The diagnosis was made by an abdominal ultrasound, which demonstrated an ileal-cecal intussusception that ultimately required surgical reduction. This case illustrates an insidious and poorly understood presentation of a common childhood affliction, as well as the utility of abdominal ultrasound in evaluating a hemodynamically stable patient with intussusception.