Vomiting in a newborn refers to the forceful expulsion of stomach contents, and while occasional spitting up of small amounts after feeding is common and generally harmless in infants, true vomiting — particularly when repeated, forceful, or containing certain colors — is treated differently by a care team because it can be an early sign of a more serious underlying problem.
The color and character of a newborn's vomit provide important diagnostic clues. Vomit that is clear or contains only recently swallowed milk is generally less concerning than vomit that is bright green or yellow-green, known as bilious vomiting, which indicates that bile, a digestive fluid normally found further along the intestine, has backed up into the stomach. Because bilious vomiting in a newborn points toward a possible blockage in the intestine, it is treated as a medical emergency until proven otherwise, regardless of how well the baby otherwise appears.
Causes and Risk Factors of Vomiting in Newborns
Bilious vomiting in a newborn is most concerning as a sign of intestinal malrotation with volvulus, a condition in which the intestine has not rotated into its normal position during development and can twist on itself, cutting off its own blood supply — a situation that requires urgent surgical evaluation because delayed treatment can lead to loss of the affected bowel.
Other causes of bilious or persistent vomiting in a newborn include intestinal atresia, in which a segment of intestine failed to form a normal passage, Hirschsprung's disease, in which nerve cells needed for normal bowel movement are missing from part of the intestine, and meconium ileus, a blockage caused by unusually thick meconium.
Non-bilious vomiting, meaning vomit without a green or yellow-green tint, is somewhat less urgent but can still indicate conditions such as duodenal atresia, pyloric narrowing, infection, or, most commonly, overfeeding or normal reflux that does not require treatment. Because the distinction between a benign cause and a surgical emergency often cannot be made by appearance alone, any bilious vomiting in a newborn is evaluated urgently regardless of how the baby otherwise looks.
When to Seek Medical Care
Any vomiting that is green or yellow-green in color should be treated as an emergency and evaluated immediately, since this is one of the clearest early warning signs of a potential intestinal blockage in a newborn. Vomiting that is forceful, persistent, increasing in frequency, or accompanied by a swollen or firm abdomen, blood in the vomit or stool, decreased activity, or a failure to pass stool normally should also be evaluated promptly. Even non-bilious vomiting that continues beyond what seems like normal spit-up, or that is affecting a baby's weight gain or hydration, warrants a conversation with your baby's care team. When in doubt about the color or significance of a newborn's vomiting, it is always safer to seek prompt evaluation than to wait and observe.