Illnesses > Illness at any age > Vomiting (Gastroenteritis)

Vomiting (Gastroenteritis)

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Vomiting with diarrhea (gastroenteritis) is a common illness.  Most cases of vomiting are caused by one of several viruses infecting the intestinal tract.  Typically, a child with gastroenteritis will vomit for several hours, sometimes up to a day before stopping; and then diarrhea will ensue, often lasting several days.

Sometimes gastroenteritis may be caused by one of several bacteria.  Mild food poisoning may have a similar course to viral gastroenteritis, but usually ends within a day or so.  If vomiting persist for longer than a day without the development of diarrhea, the child should be examined to rule out any other cause.

Gastroenteritis is generally a self-limited illness, requiring only supportive treatment.  The purpose of treatment is to make the child as comfortable as possible, and avoid significant dehydration, while waiting for the illness to pass.  You should call if you suspect that your child may be significantly dehydrated.

A child with gastroenteritis should be offered clear liquids until the vomiting has stopped.  Pedialyte® (any variety or other brand) is best for infants under 12 months. Pedialyte® is also good for the older vomiting child, but he may not enjoy the flavor;  flat clear soda or clear fruit juice may be better tasting.

You can use the following instructions as a starting point:

  1. Nothing by mouth until the child has not vomited for 2 hours.
  2. 1 teaspoon every 10 minutes for 1 hour   (1 oz. in the hour)
  3. 1 tablespoon every 15 minutes for 1 hour  (2 oz. in the hour)
  4. 1 ounce every 20 minutes for 1 hour  (3 oz. in the hour)
  5. 1 ounce every 15 minutes for 1 hour  (4 oz. in the hour)

Then liberalize, and allow the child to drink.  (Encourage at least 2 ounces per hour while awake.)

  • If the child vomits, go back to Step 1 and wait another 2 hours before starting over.
  • If the child falls asleep, let him sleep.  When he awakes, restart (above) where you left off.
  • If the child is still vomiting in the morning, please contact us in the morning.  (The child may need to be re-examined, or at least re-weighed.)
  • If there is no vomiting after 8 hours, you may try a "BRAT" diet (bananas, rice, applesauce, toast with clear jelly, etc.).  Some children enjoy rice with a little cinnamon and sugar.  (For infants, try formula diluted half-and-half with tap water.)
  • If there is no vomiting after 24 hours, you may restart the child on a regular diet.


Most children with viral gastroenteritis will develop diarrhea within a day or two of the onset of the vomiting.  The diarrhea may take a week to slowly resolve.  This is uncomfortable; you may give acetaminophen or ibuprofen for fever, stomach cramps or sore bottoms.  But diarrhea alone is not dangerous.  Children generally can drink enough avoid dehydration, despite diarrhea, once the vomiting has ended.  You can apply diaper cream (of any type) liberally and frequently to avoid raw bottoms.

Once your child has stopped vomiting for 8 hours, he needs to rehydrate.  Occasionally a child who feels ill but whose vomiting has resolved will refuse all intake.  If he doesn't eat, that's OK.  But if he doesn't drink, he will become dehydrated.  You may need to physically force fluids, by holding his hands and dribbling fluids in with a spoon or syringe.  Don't be afraid to force fluids by mouth if he resists.  In this way, you can avoid the need for IV hydration.