Most baby throw up looks like partially digested milk, often white or off-white with a lumpy, curdled texture similar to cottage cheese. This happens because stomach acid begins breaking down breast milk or formula almost immediately, so anything that comes back up even a few minutes after feeding will look thicker and chunkier than what went in. The appearance changes based on how long the milk sat in the stomach, what your baby ate, and whether the vomiting is forceful or a gentle flow.
Spit-Up vs. Vomit
Spit-up is an easy, gentle flow of stomach contents back through the mouth. It typically amounts to just one or two mouthfuls and dribbles out without much effort from your baby. Most babies spit up regularly in the first year, and it rarely bothers them.
Vomiting is different. It comes out with force, shooting from the mouth rather than oozing. Your baby’s abdominal muscles contract, and the volume is usually larger. A baby who vomits once after a feeding and seems fine afterward is not necessarily cause for alarm, but repeated forceful vomiting is worth paying attention to.
What Each Color Means
White or Off-White
This is the most common color and almost always normal. Fresh breast milk or formula that hasn’t been in the stomach long comes up looking milky white. If it’s been sitting a bit longer, it curdles into soft white lumps. Both are typical.
Clear
Clear vomit usually means your baby’s stomach was mostly empty, containing just saliva or stomach fluid. You might see this between feedings or if your baby has already thrown up everything they ate.
Yellow
A small amount of yellow in a breastfed baby’s vomit can simply be colostrum (the early, yellowish breast milk) and is usually harmless as long as it happens infrequently and in small amounts. However, bright yellow vomit can also indicate bile in the stomach, which signals something more serious.
Green
Green vomit is the single most important color to recognize. Green, bile-stained vomit in an infant is treated as a possible bowel obstruction until proven otherwise. Conditions like intestinal malrotation, where the bowel is twisted, can cause this. If your baby vomits anything that looks lime green, this warrants immediate medical evaluation.
Red, Pink, or Brown
Seeing blood in your baby’s vomit is alarming, but the most common cause is actually swallowed maternal blood. Babies can swallow blood during birth or while breastfeeding from cracked or bleeding nipples. That blood irritates the stomach lining and often triggers vomiting. The color depends on how long the blood has been in the stomach: fresh blood looks red or pink, while older blood turns dark brown and can resemble coffee grounds. If you see anything that looks like coffee grounds in your baby’s vomit, contact your pediatrician promptly.
Projectile Vomiting
Projectile vomiting is exactly what it sounds like: the contents of the stomach launch out with enough force to travel several inches or even across a room. If this happens once, it could just be a particularly forceful episode. If it happens repeatedly, especially within 30 minutes to an hour after feeding, it may point to pyloric stenosis.
Pyloric stenosis is a condition where the muscle controlling the exit of the stomach thickens and narrows, preventing milk from passing through to the intestines. Symptoms typically appear between 3 and 6 weeks of age, though they can develop as late as 5 months. A telltale sign, besides the projectile vomiting itself, is a visible wavelike motion across your baby’s stomach right after eating, just before they vomit. Babies with pyloric stenosis are hungry again almost immediately because the food never made it past the stomach. The condition is correctable with a straightforward surgical procedure.
Vomiting Triggered by Specific Foods
Once babies start eating solid foods, a pattern worth knowing about is Food Protein-Induced Enterocolitis Syndrome, or FPIES. Unlike a typical food allergy that causes hives or swelling within minutes, FPIES causes delayed, repetitive vomiting 1 to 4 hours after eating a specific food. There are no skin rashes or breathing problems. Instead, the baby vomits repeatedly, often becomes pale and unusually limp or lethargic, and may develop diarrhea within 5 to 10 hours.
FPIES can look like a stomach bug the first time it happens, which makes it tricky to identify. The key clue is that the same intense reaction happens again after the same food. Common triggers include cow’s milk, soy, grains like rice and oats, and sometimes fish or egg. If your baby has had two separate episodes of severe vomiting a few hours after eating the same food, that pattern is worth bringing to your pediatrician’s attention.
Signs of Dehydration After Vomiting
The biggest practical risk of repeated vomiting in babies is dehydration, and young infants can dehydrate faster than adults realize. Watch for fewer than six wet diapers in a 24-hour period, or going longer than eight hours without urinating. Other physical signs include dry or cracked lips, a sunken soft spot on the top of the head, sunken eyes, wrinkled skin, and crying with little or no tears.
For babies between 6 months and 1 year, the best fluid to offer after vomiting is undiluted breast milk or formula in small, frequent amounts. If your baby can’t keep that down, a commercial oral rehydration solution with balanced sugars and salts is the next step. Plain water is not recommended for babies under 1 year because it lacks the electrolytes they need. For toddlers over 1, diluted apple juice (half water, half juice) or oral rehydration solution both work. The goal during the first 24 hours is at least 1 ounce of fluid per hour, offered in small sips every few minutes rather than large amounts at once.
Colors and Patterns That Need Attention
Not every episode of vomiting requires a phone call, but certain visual cues do. The following warrant prompt medical evaluation:
- Green or bile-colored vomit, which can indicate a bowel obstruction
- Blood or coffee-ground appearance, especially if your baby hasn’t been breastfeeding from cracked nipples
- Repeated projectile vomiting after most or all feedings
- Vomiting that starts for the first time after 6 months of age, when reflux-related spit-up should be improving rather than worsening
- Signs of dehydration like a sunken soft spot, no tears, or significantly fewer wet diapers
The vast majority of infant spit-up and occasional vomiting is messy but harmless. White, curdled, cottage-cheese-textured spit-up after a feeding is one of the most normal things a new baby does. Color, force, timing, and frequency are the details that separate routine mess from something that needs medical attention.