The most important thing to feed a baby with a stomach bug is fluids, not food. Dehydration is the real danger with infant gastroenteritis, so replacing lost fluids takes priority over solid meals. If your baby is breastfeeding, keep breastfeeding. If they’re on formula, keep offering formula. And if they’re old enough for solids, hold off on food for about eight hours after vomiting starts, then reintroduce bland options gradually.
Keep Breastfeeding or Formula Going
If your baby is breastfed, do not stop. Breast milk is both nutrition and hydration in one, and it’s gentle enough on the stomach to serve as rehydration therapy on its own. Offer the breast more frequently than usual, even if feedings are shorter. Babies who are exclusively breastfed should not be switched to other fluids or foods as a replacement during illness.
For formula-fed babies, continue offering formula at normal strength. There’s no need to dilute it. Smaller, more frequent bottles tend to stay down better than full-size feedings. If your baby vomits a full bottle, wait 15 to 20 minutes and try again with a smaller amount, around one to two ounces at a time.
When and How to Use Oral Rehydration Solutions
If your baby is showing signs of dehydration (fewer wet diapers, no tears when crying, dry mouth, or unusual sleepiness), an oral rehydration solution like Pedialyte can help replace both fluids and electrolytes. These solutions are specifically designed for infants and young children, with the right balance of salt and sugar to help the gut absorb water efficiently.
The amount depends on your baby’s size. As a rough guide for the first four hours of rehydration:
- Under 6 kg (about 13 lbs): 200 to 400 ml (7 to 14 oz)
- 6 to 10 kg (13 to 22 lbs): 400 to 700 ml (14 to 24 oz)
- 10 to 12 kg (22 to 26 lbs): 700 to 900 ml (24 to 30 oz)
A simple formula: multiply your baby’s weight in kilograms by 75 to get the total milliliters for that first four-hour window. Offer it in small, frequent sips or with a syringe if your baby refuses a bottle. Don’t give it all at once.
Reintroducing Solid Foods
If your baby is old enough for solids (typically six months and up), wait about eight hours from the start of vomiting before offering any food. Pushing solids too early often triggers more vomiting and makes the whole experience worse for everyone.
Once your baby can hold fluids down, start with bland, easy-to-digest foods. Good first options include:
- Bananas: soft, binding, and rich in potassium (which is lost during diarrhea)
- Plain rice cereal or white rice: low fiber and easy on the gut
- Applesauce: unsweetened only
- Plain toast: for older babies who handle bread well
- Plain yogurt: provides some beneficial bacteria alongside gentle protein
Serve tiny portions. A few spoonfuls at a time is plenty. If it stays down, you can offer more 30 to 60 minutes later. Most babies won’t have much appetite during a stomach bug, and that’s completely normal. Don’t force food. Focus on fluids and follow your baby’s cues.
What Not to Give
Sugary drinks are the biggest mistake parents make during a stomach bug. Juice, soda, sports drinks, and flavored waters all contain enough sugar to pull extra water into the intestines, which makes diarrhea worse. Children under 12 months shouldn’t have juice at all, and even toddlers over 12 months should skip it during illness. Fruit-flavored drinks and juice “cocktails” are even worse because they contain added sugars on top of the natural sugar.
Also avoid greasy, fried, or heavily seasoned foods. High-fat foods are harder to digest and can trigger more vomiting. Stick with the bland options above until your baby’s stomach has clearly settled, usually a day or two after the last episode of vomiting or diarrhea.
Probiotics May Shorten the Illness
A large meta-analysis of 25 clinical trials covering more than 5,000 children found that probiotics significantly reduced the duration of both diarrhea and vomiting during stomach bugs. The diarrhea benefit was measurable by day two and continued through day five. The most commonly studied strains were Lactobacillus and Saccharomyces species, which are found in many infant-specific probiotic supplements.
If you want to try a probiotic, look for one formulated specifically for infants. These come in drops or powder that can be mixed into breast milk or formula. They won’t stop the illness immediately, but they may trim a day or so off the worst symptoms.
Signs That Need Immediate Attention
Most stomach bugs in babies resolve on their own within a few days. But certain warning signs mean something more serious could be happening.
Bright green vomit is a red flag. Yellow vomit is normal stomach acid, but green vomit can indicate a bowel obstruction, which is a surgical emergency. If your baby vomits anything bright green and hasn’t been drinking a green-colored liquid, get to an emergency room.
A tender belly is another concern. While your baby is distracted with a toy, gently press on their stomach. You should be able to press in about an inch without a reaction. If your baby screams, winces, or pulls away, that suggests something beyond a routine stomach bug.
Babies under one month old who have any fever or just look “off,” whether that means poor feeding, unusual sleepiness, or pale color, need immediate medical evaluation. Their immune systems can’t handle infections the way older babies can, and what looks like a simple stomach bug may be something else entirely. For older babies, watch for signs of worsening dehydration: no wet diaper in six or more hours, sunken soft spot on the head, or listlessness that goes beyond normal tiredness.