Baby vomit can look surprisingly different depending on what your baby ate, how long ago they ate it, and whether something more serious is going on. In most cases, what parents see is spit-up: a gentle flow of milk that dribbles out of the mouth, usually just one or two mouthfuls at a time. True vomiting is forceful, shooting out rather than oozing, and the contents can range from white and milky to curdled, yellow, green, or even tinged with red or brown.
Understanding what each color and texture means can help you tell the difference between a normal mess and something that needs medical attention.
Spit-Up vs. Actual Vomiting
The most important distinction is effort. Spit-up flows easily from a baby’s mouth, often right after a feeding or during a burp. It typically amounts to one or two mouthfuls of breast milk or formula, and the baby usually seems unbothered by it. It can look like fresh milk, slightly curdled milk, or clear liquid, and it’s a normal part of infancy for most babies.
Vomiting is different. It comes out with force, sometimes propelled several inches or more from the baby’s mouth. The baby’s abdominal muscles visibly contract, and infants often look distressed before, during, or after. A single episode of forceful vomiting isn’t always cause for alarm, but repeated forceful vomiting, especially if your baby seems uncomfortable or isn’t feeding well afterward, is worth paying attention to.
White, Clear, or Curdled
The most common appearance of baby vomit is some version of the milk they just drank. If the feeding was recent, it may look almost identical to breast milk or formula. If some time has passed, stomach acid begins to break down the milk proteins, giving the vomit a lumpy, cottage cheese-like texture. This curdled look alarms many parents, but it’s completely normal and just means digestion had already started.
Clear or mucus-like vomit is also common, particularly if the baby’s stomach was mostly empty or if they’ve been swallowing extra saliva. Newborn spit-up can look curdled, non-curdled, white, yellow, clear, or mucus-like, all within the range of normal.
Yellow Vomit
Yellow vomit can mean a few things. In younger babies, it sometimes reflects partially digested breast milk or formula that has spent more time in the stomach. But yellow can also indicate the presence of bile, a digestive fluid produced by the liver that enters the intestine just below the stomach.
Yellow vomiting on its own doesn’t automatically signal a surgical emergency, but it shouldn’t be dismissed either. The clinical state of the baby matters most. If a baby with yellow vomit is otherwise feeding well, gaining weight, and alert, it’s less concerning than if the baby appears lethargic, is refusing feeds, or has a swollen belly. Bile in vomit is considered an independent sign of disease severity and is rarely seen in well infants.
Green Vomit
Bright green or neon-green vomit is the color that warrants the most urgency. Green vomit in a newborn is treated as a surgical emergency until proven otherwise, because it can signal an intestinal obstruction. Bile is naturally green, and when it appears in vomit, it means something may be blocking the intestine below the point where bile enters the digestive tract.
Conditions that cause this include intestinal malrotation (where the bowel is twisted into an abnormal position), intestinal atresia (a section of bowel that didn’t form properly), and Hirschsprung’s disease. In the case of a bowel twist, green vomiting may be the only early sign, and rapid diagnosis is essential to prevent the blood supply to the intestine from being cut off. If your baby vomits bright green liquid, especially in the first few weeks of life, this needs immediate medical evaluation.
Pink, Red, or Brown Vomit
Any shade of red in baby vomit understandably alarms parents, but the most common cause in newborns is swallowed blood from the mother. During delivery, babies can swallow small amounts of maternal blood, and breastfed newborns frequently ingest blood from cracked or bleeding nipples. This swallowed blood then comes back up looking pink, red, or sometimes dark brown, resembling coffee grounds if the blood has been partially digested by stomach acid.
A simple lab test can determine whether blood in vomit belongs to the mother or the baby by distinguishing between maternal and infant blood cells. If you’re breastfeeding and notice pink-tinged or streaky red spit-up, check your nipples for cracks or sores first. That said, any significant amount of blood in vomit, or blood that can’t be explained by a nipple injury, needs medical evaluation.
Projectile Vomiting
Projectile vomiting is exactly what it sounds like: the stomach contents shoot out with enough force to travel several feet. While occasional forceful vomiting can happen with any stomach upset, repeated projectile vomiting after feedings in babies between 3 and 6 weeks old is the hallmark of pyloric stenosis. This condition occurs when the muscle controlling the outlet of the stomach thickens and narrows, preventing milk from passing through to the intestines.
Babies with pyloric stenosis are typically hungry right after vomiting because the food never made it past the stomach. The vomit usually looks like curdled or partially digested milk rather than bile-stained, since the blockage is above the point where bile enters. Pyloric stenosis is rare after 3 months of age. If your baby is in that 3-to-6-week window and vomiting forcefully after most feedings, this is something your pediatrician will want to evaluate quickly.
Vomiting With a Stomach Bug vs. Food Sensitivity
Gastroenteritis, the common stomach bug, is one of the most frequent causes of vomiting in babies beyond the newborn period. It typically comes with fever and diarrhea (sometimes with blood in the stool), and the vomiting tends to resolve within 24 to 48 hours. The vomit itself looks like whatever was recently eaten, progressively becoming more watery or clear as the stomach empties.
A food protein sensitivity called FPIES looks quite different. It causes profuse, repetitive vomiting, usually starting one to four hours after eating a trigger food. What sets FPIES apart from a stomach bug is the absence of fever. Babies with FPIES often become pale, floppy, and lethargic during an episode, without the typical signs of infection. FPIES reactions are most often triggered by common foods like milk, soy, rice, or oats when they’re first introduced.
Signs of Dehydration to Watch For
The biggest risk with any type of repeated vomiting is dehydration, and babies can dehydrate faster than older children or adults. The most reliable way to track hydration at home is through wet diapers. A newborn under 4 months should have at least 6 wet diapers in a 24-hour period. A baby older than 4 months should have at least 3.
Beyond diaper counts, physical signs of dehydration in babies include a dry or sticky mouth, crying without producing tears, sunken-looking eyes, and a soft spot on top of the head that looks flat or pulled inward rather than slightly rounded. More advanced dehydration can cause rapid breathing and unusual sleepiness or difficulty waking the baby. If your baby is vomiting repeatedly and showing any of these signs, they need fluids and medical attention promptly.