Non-bilious vomiting in newborns with pyloric stenosis typically begins at what age?

Non-bilious vomiting in newborns with pyloric stenosis usually begins around 2 to 4 weeks of age. This condition is characterized by hypertrophy of the pylorus, the opening from the stomach to the small intestine, which leads to gastric outlet obstruction.

At around 2 to 4 weeks of life, infants may start displaying signs of non-bilious vomiting after feeding, as the narrowing at the pylorus prevents food from passing into the intestines. This vomiting is typically characterized by projectile nature and occurs shortly after feeding. The timing corresponds with the maturation of the condition, as it often manifests as the child begins to feed more frequently and consume larger volumes.

Earlier than 2 weeks, symptoms may not be as apparent as the condition may not yet be fully developed. Conversely, if vomiting begins after 4 weeks, it could suggest a different underlying issue rather than pyloric stenosis, as the classic presentation typically occurs within that 2 to 4-week window. Understanding this timeline is crucial for healthcare providers to make an accurate diagnosis and ensure timely intervention.