Q. My 4-year-old has been vomiting on and off for a few days. What might be wrong with her and what should I do?
A. She's likely suffering from gastroenteritis, commonly called the stomach flu, which is a viral inflammation of the stomach and the intestines. When this happens, the stomach rejects food as a way of saying "Don't fill me up. I need rest." Your child's illness -- which is very contagious while she's still vomiting -- should steadily get better within a few days and last a week at most. In the meantime:
Replace lost fluids, since dehydration is the most serious side effect of persistent vomiting, especially if it's accompanied by diarrhea. Start with small sips of clear, noncarbonated beverages every five to ten minutes. While plain water is fine, your child also needs to drink liquids that contain the necessary amounts of sugar and salt. For vomiting that lasts for more than a day, your best bet is an oral electrolyte solution. Also, I like to recommend white grape juice -- you can dilute it with water if your child has trouble keeping it down. Popsicles or slushies made with these beverages are nice options too.
Avoid very sugary drinks, such as apple or pear juice, which can cause bloating and aggravate the diarrhea.
Once your child hasn't vomited or experienced abdominal discomfort for eight hours, slowly give her more fluids and small portions of bland foods, such as crackers, bananas, boiled potatoes, toast, broth, and yogurt.
After she's able to tolerate these foods for a day, gradually resume her normal diet.
Call your doctor if you notice signs of dehydration, such as dry eyes, skin, or mouth; less frequent urination (half as often as usual); dark-yellow urine; and no tears when crying. If after a few days your child seems to be getting sicker -- with fever, more frequent diarrhea, or body aches and chills -- or if the vomit becomes green or bloody, she might have a more serious infection that warrants immediate medical attention.