Vomiting is a natural defense mechanism. When the immune system of the intestinal tract and liver detect certain viruses and toxins – a stimulus to vomit is sent out. The intensity of vomiting can vary according to the nature of the toxin or virus, the amount ingested, and the person’s age and tolerance. Morning sickness is an example of a super-sensitive or overactive vomiting reflex, but the enhanced sense of smell and food aversions of pregnancy demonstrate the body’s attempt to protect the fetus.
When a family gets exposed to a stomach viruses like Norwalk or Rota virus, younger children can throw up more violently and be more at risk for dehydration. Also, they can resist taking fluids they don’t like and spit it back if the parents try to force feed them.
Typically, the urge to vomit is strongest in the first eight hours. If a child drinks rapidly, they often throw it all up. Small amounts of fluid are more likely to be retained. As the immune system kicks in, the intensity of the vomiting urge will start to fade, and more fluid can be introduced. After taking a nap, or sleeping through the night, the person might be able to drink more without vomiting.
Give small amounts of fluid during the first wave: for children, about 1 tablespoon of a clear sugar containing liquid like ginger ale every 10 minutes. Both ginger and cola drinks have an ‘anti-nausea’ effect and also ‘calm’ the stomach. Little children are more sensitive to the caffeine in cola drinks.
Babies should be given pedialyte or other electrolyte solution. Give about a teaspoon every 10 minutes for the first 8 hours. If the baby doesn’t want to take it from a bottle, use a medicine syringe and aim in towards the inner cheek. Stroking the side of the child’s face or neck will help them swallow it. However, this technique sometimes requires two adults, one to hold the child and the other to place the syringe in the child’s mouth and stroke their cheek.
Breastfed babies should continue breastfeeding. It will help relax and sooth the baby. However, keep track of how often the baby vomits and replace each episode with about one and a half ounces of electrolyte solution.
Formula fed babies might cry for the bottles, and you can give pedialyte. If they resist and seem to demand formula, give them diluted formula. Add an ounce of water to an ounce of formula, and then add two ounces of pedialyte. Hold off straight formula until about 8 hours after vomiting has subsided.
Phase two: The Vomiting Urge starts to subside.
After the first wave of the illness, (usually 8-10 hours) the nausea sensation will start to wane. Now you can offer more fluid and give the child simple, easily digested foods like crackers or toast. After vomiting, a child can benefit from high potassium foods like mashed potatoes, mashed carrots or bananas. Another idea is cutting an orange into sections and letting them suck out the juice. Don’t give anything that’s hard to digest or chunky because the child can still throw up and you don’t want them throwing up any large particles of food.
Continue offering the child electrolyte solution to replace the fluid they lost during the first phase of illness. Infants and toddlers can be given formula or milk again. However, if they have diarrhea, you will need to keep replacing ongoing losses with pedialyte.
Phase three: Recovery
Keep the child on simple, easily digested foods. Watch out for diarrhea and continue replacing any ongoing fluid losses with electrolyte solution. It is a good idea to avoid high allergy foods like peanut butter, nuts and shell fish in the days after an intestinal illness because the immune system along the intestinal lining is in a more “activated” state and can direct itself against food allergens.
Special note: after viral infections, the lymph nodes along the intestinal tract are slightly enlarged. Children’s lymph nodes are larger proportionately than adults and the area around the appendix has a high concentration of lymph nodes. If someone develops abdominal pain around the right lower abdomen after a stomach virus, this could herald appendicitis. Appendicitis can start with nausea and mild pain around the belly button that then travels to the right lower quadrant. Sometimes, however, it’s in an atypical location; midline or even deflected to the left.
Many vomiting illnesses will be followed by diarrhea. See the article on Vomiting and Diarrhea, along with the one on Diarrhea.