Help the sick child rinse her mouth, but don't give liquids or foods until the vomiting has stopped - say, after an hour without vomiting. Vomiting that lasts four hours needs attention. So, if your child throws up after supper and continues to throw up until 10 p.m., call your doctor. Don't wait if the child is lethargic, appears dehydrated, or is in pain. Call immediately if the vomit shows blood or bile.
Blood can be red, meaning it is fresh, or black, meaning it is old.
Black or green material in the vomit can be bile, which means the child may have a serious obstruction. Green can also be candy or salad, but call anyway. When a child does quit vomiting, give some water. Diarrhea Frequent diarrhea demands lots of fluids, since the first serious effect can be dehydration. It's best not to offer boiled milk or other so-called remedies.