Newborns need no extra water. Breast milk or infant formula generally will supply enough fluid.
If your child is sick with mild diarrhea or vomiting, keep breast-feeding if you are nursing. Breast-feeding helps prevent diarrhea, and your baby may recover quicker. If you are using formula, make it full strength unless your health care provider gives you different advice.
Check with your baby’s health care provider about replacing fluids if your baby is sick. Diarrhea and vomiting can lead to dehydration — and make your baby quite sick — if fluids aren't replaced. But rather than water, a sports drink, or juice (which can make diarrhea worse), your doctor or pediatric nurse may recommend an oral rehydration solution. These products are sold near baby foods in your grocery store. Besides fluid, the solution contains glucose (a form of sugar) and minerals (sodium, chloride and potassium) called electrolytes. Electrolytes help maintain fluid balance in your baby's body cells. These minerals are lost with diarrhea or vomiting. An oral rehydration solution won't stop the diarrhea or vomiting, but it does prevent dehydration.
Before feeding an oral rehydration solution to children under two years of age (or children of any age), consult your child’s health care provider. Additional reasons to contact your baby’s health care provider:
- If your baby is a newborn (under 3 months old) and has diarrhea.
- If you see signs that your child may be getting dehydrated: dry lips, mouth, and tongue; no tears when crying; no wet diaper for 3 hours; or faster than usual heartbeat. Signs of more serious dehydration include sunken eyes or fontanelle (the soft spot on top of the head) or being much less active or attentive than usual.
- If fever and diarrhea or vomiting continues for more than 24 hours.
It’s important that you check with them rather than trying to manage replacing fluids for your baby on your own, because besides the risk of dehydration, diarrhea and vomiting sometimes signal an illness that requires medical attention. Avoiding dehydration is important, but that alone does not solve the underlying problem.
On the other hand, diarrhea in babies usually does not last long. Most often, it is caused by a virus and goes away on its own, or is a temporary response to a change in the baby’s (or a breast-feeding mother’s) diet.