Vomiting can be caused by many things. Most of the time, vomiting in children is caused by gastroenteritis, usually due to a virus infecting the gastrointestinal tract. Gastroenteritis, often called the "stomach flu," also can cause nausea and diarrhea.

These infections usually don't last long and are more disruptive than dangerous. However, kids (especially infants) who cannot take in enough fluids and also have diarrhea could become dehydrated.

It's important to stay calm — vomiting is frightening to young children (and parents, too) and exhausting for kids of all ages. Reassuring your child and preventing dehydration are key for a quick recovery.

Over-the-counter medications to treat nausea, vomiting, and diarrhea are not recommended for infants and children. Doctors might recommend medication for nausea or vomiting in certain situations, but these are available only by prescription.

Oral rehydration is something parents can do at home to help prevent dehydration or treat mild cases. Talk to your doctor, especially if you think your child is dehydrated, as you might be given alternate instructions on how to orally rehydrate your child.

Oral Rehydration Tips

For Infants Younger Than 6 Months

• Avoid giving plain water to an infant unless your doctor directly specifies an amount.
• Offer your baby small but frequent amounts — about 2-3 teaspoons, or up to ½ ounce (about 20 milliliters) — of an oral electrolyte solution every 15-20 minutes with a spoon or an oral syringe. Oral electrolyte solutions (available at most supermarkets or pharmacies and also called oral electrolyte maintenance solutions) are balanced with salts to replace what's lost from vomiting or diarrhea, and they also contain some sugar. It's especially important for infants that any fluids given have the correct salt balance (unflavored electrolyte solutions are best).
• Gradually increase the amount of solution you're giving if your infant is able to keep it down for more than a couple of hours without vomiting. For instance, if your little one takes 4 ounces (or about 120 milliliters) normally per feeding, slowly work up to giving this amount of oral electrolyte solution over the course of the day.
• Do not give more solution at a time than your baby would normally eat — this will overfill an already irritated tummy and likely cause more vomiting.
• After your infant goes for more than about 8 hours without vomiting, reintroduce formula slowly if your infant is formula-fed. Start with small (½-1 ounce, or about 20-30 milliliters), more frequent feeds and slowly work up to the normal feeding routine. If your infant already eats baby cereal, it's OK to start solid feedings in small amounts again.
• If your infant is exclusively breastfeeding and vomits (not just spits up, but vomits what seems like the entire feeding) more than once, then breastfeed for a total of 5-10 minutes every 2 hours. If your infant is still vomiting, call your doctor. After 8 hours without vomiting, you can resume breastfeeding normally.
• If your infant is under 2 months old and vomiting (not just spitting up) all feedings, call your doctor immediately.

For Infants 6 Months to 1 Year

• Avoid giving plain water to an infant under 1 year unless your doctor directly specifies an amount.
• Give your baby small but frequent amounts — about 3 teaspoons, or ½ ounce (about 20 milliliters) — of an oral electrolyte solution every 15-20 minutes. It's important that any fluids given have the correct salt balance (again, oral electrolyte solutions are balanced with salts to replace what's lost with vomiting or diarrhea).
• An infant over 6 months old may not appreciate the taste of an unflavored oral electrolyte solution. Flavored solutions are available or you can add ½ teaspoon (about 3 milliliters) of juice to each feeding of unflavored oral electrolyte solutions. Frozen oral electrolyte solution pops are often appealing to infants this age and this approach also encourages the required slow intake of fluids.
• Gradually increase the amount of solution you're giving if your baby keeps it down for more than a couple of hours without vomiting. For instance, if your infant takes 4 ounces (about 120 milliliters) normally per feeding, slowly work up to giving this amount of oral electrolyte solution over the course of the day.
• Do not give more solution at a time than your infant would normally eat — this will overfill an already irritated tummy and likely cause more vomiting.
• After your baby goes more than about 8 hours without vomiting, you can reintroduce formula slowly. Start with small (1-2 ounces, or about 30-60 milliliters), more frequent feedings and slowly work up to the normal feeding routine. You also can begin giving small amounts of soft, bland foods that your infant is already familiar with such as bananas, cereals, crackers, or other mild baby foods.
• If your infant doesn't vomit for 24 hours, you can resume your normal feeding routine.

Oral Rehydration Tips

For Kids 1 Year and Older:

• Give clear liquids (milk and milk products should be avoided) in small amounts ranging from 2 teaspoons to 2 tablespoons, or up to 1 ounce or 30 milliliters depending on how much your child can tolerate, every 15 minutes.
  
  Appropriate clear liquids include:
  • ice chips or sips of water
  • flavored oral electrolyte solutions, or add ½ teaspoon (about 3 milliliters) of nonacidic fruit juice to the oral electrolyte solution
  • frozen oral electrolyte solution pops
• If your child vomits, start over with a smaller amount of fluid (2 teaspoons, or about 5 milliliters) and continue as above.
• If there's no vomiting for approximately 8 hours, introduce bland, mild foods gradually. But do not force any foods — your child will tell you when he or she is hungry. Saltine crackers, toast, broths, or mild soups (some noodles are OK), mashed potatoes, rice, and breads are all OK.
• If there's no vomiting for 24 hours, slowly resume the regular diet. Wait 2-3 days before resuming milk products.

When to Call the Doctor

The greatest risk of vomiting due to gastroenteritis is dehydration. Call your doctor if your child refuses fluids or if the vomiting continues after using the suggested rehydration methods.

Call the doctor for any of these signs of dehydration:

Mild to moderate dehydration:

• dry mouth
• few or no tears when crying
• fussy behavior in infants
• fewer than four wet diapers per day in an infant (more than 4-6 hours without a wet diaper in babies under 6 months of age)
• no urination for 6-8 hours in children
• soft spot on an infant's head that looks flatter than usual or somewhat sunken

Severe dehydration:

• very dry mouth (looks "sticky" inside)
• dry, wrinkled, or doughy skin (especially on the belly and upper arms and legs)
• inactivity or decreased alertness
• appears weak or limp
• sunken eyes
• sunken soft spot in an infant
• excessive sleepiness or disorientation
• deep, rapid breathing
• no urination for more than 6-8 hours in infants
• no urination for more than 8-10 hours in children
• fast or weakened pulse

These symptoms may indicate a condition more serious than gastroenteritis; contact your doctor right away:

• projectile or forceful vomiting in an infant, particularly a baby who's less than 3 months old
• if your infant is under 2 months old and vomiting (not just spitting up)
• vomiting after your baby has taken an oral electrolyte solution for close to 24 hours
• vomiting starts again as soon as you try to resume your child's normal diet
• vomiting starts after a head injury
• vomiting is accompanied by fever (100.4°F/38°C rectally in an infant under 6 months old or more than 101-102°F/38.3-38.9°C in an older child)
• vomiting of bright green or yellow-green fluid, blood, or vomit resembling coffee grounds (blood that mixes with stomach acid will be brownish and look like coffee grounds)
• your child's belly feels hard, bloated, and painful between vomiting episodes
• vomiting is accompanied by severe stomach pain
• your child is lethargic
• swelling, redness, or pain in a boy's scrotum

Vomiting due to gastroenteritis can spread to others, so your child should stay home from school or childcare until there's been no vomiting for at least 24 hours. And remember that hand washing done often and well is the best way to protect your family against many infections.

Reviewed by: Yamini Durani, MD
Date reviewed: May 2011