Bilious vomiting and an apparently reassuring abdomen

A fictional two-week-old infant develops sudden green vomiting and becomes less interactive during the morning. The abdomen is not markedly distended, and a trainee initially considers ordinary feeding reflux because there is no large visible abdominal mass. The neonatal team is concerned about an obstructive process and the possibility of compromised intestinal perfusion. No definitive imaging result, lactate trend or operative finding is supplied. The supervisor asks the trainee to distinguish an absence of one dramatic sign from evidence that the infant is safe. The case is about recognizing a potentially time-sensitive surgical presentation, communicating uncertainty and choosing the appropriate qualified pathway. It does not prescribe a home treatment, an invasive procedure or a fixed order of tests for an unstable infant.