An 11-day-old boy born at 39 weeks of gestation presented to the emergency department with watery diarrhea, bilious emesis, progressively worsening abdominal distention, and shock. There had been no complications during his birth, and he had been growing appropriately while receiving breast milk. The oxygen saturation was 82% while he was breathing ambient air; the blood pressure could not be measured. On physical examination, general cyanosis and subcostal retractions were present, and there were no audible bowel sounds. Abdominal radiography revealed gas in the bowel wall, a finding known as pneumatosis intestinalis (Panel A). The patient’s trachea was intubated, and treatment with broad-spectrum antibiotic agents, intravenous fluids, and vasopressors was initiated. Because of worsening symptoms associated with shock, an exploratory laparotomy was performed. Gas bubbles were seen within the walls of the small and large intestines (Panel B), a finding consistent with the diagnosis of necrotizing enterocolitis. Necrotizing enterocolitis is a life-threatening ischemic necrosis of the intestines that is most commonly seen in premature infants; however, certain conditions, such as congenital cardiac disease, can confer a predisposition to necrotizing enterocolitis in full-term infants. During the operation, the patient became pulseless; despite the initiation of cardiopulmonary resuscitation, the patient died. An autopsy was declined by the family.