The most important thing you can do for a baby with diarrhea is keep them hydrated and continue feeding them normally. Most infant diarrhea is caused by a viral infection, resolves within three to seven days, and can be managed safely at home. But because babies lose fluids fast, knowing how to spot dehydration and when to call your pediatrician matters more than any home remedy.
Why Babies Get Diarrhea
Viral infection is the leading cause of diarrhea in infants. Symptoms typically start 12 hours to five days after exposure and clear up within three to seven days. Bacterial infections are less common but more likely when stool is bloody or contains mucus, or when a baby has a persistent fever above 104°F (40°C). Antibiotics can also trigger diarrhea by disrupting gut bacteria, even when the medication is treating something unrelated to the digestive system.
If diarrhea lasts a week or longer, it’s considered prolonged and needs a different kind of evaluation than a standard stomach bug.
Keep Fluids Going
Babies lose water and essential minerals through loose stools much faster than adults do. If your baby is breastfeeding, continue nursing on demand. Breast milk is both hydrating and easy to digest, and there’s no reason to pause it during a bout of diarrhea. If your baby is formula-fed, keep offering formula as usual.
For babies showing early signs of dehydration (slightly dry mouth, increased thirst, fewer wet diapers), an oral rehydration solution is the gold standard. These are available over the counter and contain a specific balance of sodium, potassium, and glucose designed to replace what diarrhea pulls out. Plain water, juice, and sports drinks don’t have the right electrolyte balance for infants and can actually make things worse.
If your baby is vomiting on top of the diarrhea, offer tiny sips of oral rehydration solution, about a teaspoon every minute, rather than a full bottle at once. Small, frequent amounts are far more likely to stay down. For each watery stool your baby passes, aim to replace roughly 10 mL per kilogram of body weight. So a 7 kg (15-pound) baby would need about 70 mL (a little over 2 ounces) of extra fluid per loose stool.
Feed Normally, Skip the BRAT Diet
If you’ve heard that bananas, rice, applesauce, and toast (the BRAT diet) are the go-to foods for diarrhea, that advice is outdated. Medical guidelines now recommend continuing age-appropriate foods during acute diarrhea rather than restricting the diet. A restrictive diet like BRAT lacks the protein, fat, and micronutrients babies need, and it can actually impair nutritional recovery and, in some cases, contribute to malnutrition.
If your baby is eating solids, keep offering the foods they normally eat. A balanced mix of carbohydrates, protein, and fat supports healing better than bland starches alone. One helpful addition: a small serving of plain yogurt (1 to 2 ounces, twice a day) for babies over four to six months old. The live cultures may help restore gut balance. Avoid cow’s milk-based formulas during the illness if your pediatrician suggests switching temporarily.
Probiotics Can Shorten Recovery
There’s moderate clinical evidence that probiotics reduce the duration of diarrhea in children by roughly one day. A 2025 review published in Frontiers in Pediatrics found that children taking probiotics were also more likely to have recovered by the end of the study period compared to those given a placebo.
Not all probiotic strains work equally well. The strains with the strongest evidence for shortening diarrhea duration include Saccharomyces boulardii (a beneficial yeast), Lactobacillus reuteri, and Bifidobacterium species. Lactobacillus rhamnosus showed particular strength in reducing the overall number of children still experiencing diarrhea at the end of treatment. If you want to try a probiotic, look for infant-specific products containing one of these strains. Ask your pediatrician for a recommendation, especially for babies under six months.
Never Give Anti-Diarrheal Medications
Over-the-counter anti-diarrheal drugs like loperamide (the active ingredient in Imodium) should never be given to children under two years old. Safety and efficacy have not been established for this age group, and the medication can cause serious side effects in infants. The same goes for bismuth subsalicylate products (like Pepto-Bismol), which contain ingredients that can be toxic to babies. In general, no over-the-counter diarrhea medication is safe for infants. The treatment is fluids, food, and time.
Protect the Skin
Frequent loose stools are hard on a baby’s skin. Diaper rash during a bout of diarrhea can develop quickly and become painful. Change diapers as soon as they’re soiled, even if that means getting up at night. Rinse your baby’s bottom with warm water at each change rather than relying solely on wipes, and pat the area dry gently.
Apply a thick layer of barrier cream containing zinc oxide or petroleum jelly after every change to shield the skin from the next stool. When possible, let your baby go diaper-free for short stretches to allow air to reach the skin. Disposable diapers with absorbent gel tend to pull moisture away from the skin better than cloth during active diarrhea. Avoid any products containing baking soda, boric acid, camphor, phenol, benzocaine, or salicylates, as these ingredients can be toxic to babies.
Signs of Dehydration to Watch For
Mild dehydration looks like a slightly dry mouth, a bit more fussiness, and somewhat fewer wet diapers than usual. This is manageable at home with extra fluids and oral rehydration solution.
Moderate dehydration is more concerning. Signs include a noticeably dry mouth, sunken eyes, a sunken soft spot (fontanelle) on the top of the head, little or no urine output, loss of skin elasticity (when you gently pinch the skin on the belly or arm, it stays tented rather than snapping back), and unusual sleepiness or lethargy. A baby at this stage needs medical attention promptly.
Severe dehydration is a medical emergency. A baby with no tears when crying, rapid or weak pulse, cool or mottled skin, rapid breathing, or extreme lethargy bordering on unresponsiveness needs emergency care immediately.
When This Needs Medical Attention
Call your pediatrician or go to urgent care if your baby has any of the following:
- Blood or mucus in the stool
- Fever above 104°F (40°C)
- Green or yellow vomit (bilious vomiting), which can signal a blockage
- Diarrhea lasting longer than seven days
- Signs of moderate or severe dehydration described above
- Severe abdominal pain or a visibly swollen belly
- A rash with small red or purple dots (petechial rash)
Babies under three months old with diarrhea should be evaluated by a doctor regardless of how mild it seems. Young infants have less reserve, and dehydration can progress rapidly. The same applies to any baby with an underlying health condition.