Last night on call I got a few phone calls from worried parents who had little ones who were vomiting repeatedly. There is nothing scarier and more heart wrenching than watching your child vomit. As a pediatrician, this is a very common phone call, as well as one of the most difficult, as the list of causes is vast, and deciding how to advise the parent can be challenging.
One thing is for sure…vomiting, like fever or coughing, is the body’s way of telling us that something is going on.
What is Vomiting?
Vomiting occurs when a sudden tightening of abdominal muscles, decrease in intra-thoracic pressure, and reverse peristalsis (movement of small intestines back toward the mouth) causes a propelling of stomach contents up and through a relaxed sphincter, into the throat, and out the mouth in a rapid and forceful way. It is a complex, automatic, and reflexive event in response to a trigger of the vomiting center of the brain. This vomiting center receives signals from multiple places such as the gastrointestinal tract (stomach flu, appendicitis), the inner ear (motion sickness), bloodstream (medications, infections), or within the brain itself (migraines, smells).
What Are the Common Causes of Vomiting in Children?
The most common cause of vomiting in children is a viral gastrointestinal (GI) illness. Judging from the number of calls 
about vomiting last night, one of these viruses is circulating in the community right now! Typically viral GI illnesses cause 12-24 hours of vomiting, followed by diarrhea. They may or may not be accompanied by fever, but if your child has fever with vomiting, be sure to call the doctor. Rotavirus is one of the most common causes of severe vomiting and diarrhea in children. Due to vaccination, fortunately, the incidence and severity of Rotavirus has been dramatically decreased. Another cause of GI infection is food poisoning from bacteria such as E.coli. Frequently these infections are accompanied by severe diarrhea, often bloody, and abdominal cramping.
Bacterial infections such as ear infections, pneumonia, urinary tract infections, appendicitis, blood infections, and meningitis, can cause vomiting as well. Often, these illnesses will have other symptoms as well, including fever, which is why it is important to call your doctor if your child has fever with vomiting.
Babies under 6 weeks of age with vomiting (more forceful than spit up) may have gastrointestinal reflux (GERD), or something more significant like an obstruction in the intestinal tract, like pyloric stenosis. Metabolic diseases may also show up as vomiting in newborns. If your newborn baby is vomiting, have him or her checked as soon as possible.
Please note that children at any age can have an obstruction, and frequently the color of the vomit will be grass green. Contrary to popular belief, bile is green, not yellow. If your child’s vomit is green, call your doctor immediately.
Lastly, children with increased pressure in the brain from brain tumors, or hydrocephalus (too much fluid in the brain) will have vomiting, typically in the morning. Children with morning vomiting and headaches that awaken them at night need to be evaluated immediately.
What About Dehydration?
Dehydration is the most concerning side effect of vomiting. If your child has a viral GI illness, keeping him or her hydrated is crucial. Dehydration will only make the child sicker, and may cause more vomiting. Signs of dehydration are as follows:
- No urine output in over 6 hours
- Rapid heart rate
- Cracked lips or dry tongue
- Lack of tears
- Extreme lack of energy / lethargy
If your child has any of these symptoms, call your doctor.
How Can I Maintain Hydration During a Vomiting Illness?
Keeping a vomiting child hydrated can be very hard. The key to being successful at this is giving the right liquids in the right quantities. The intestinal tract will absorb water faster and more efficiently if it is facilitated by salt (sodium) and sugar (glucose). Therefore, the best rehydration liquids, or oral rehydration solutions (ORS) are drinks like Pedialyte, Gatorade, or breast milk, NOT plain water. Have some Pedialyte or Gatorade available for this purpose at home at all times (these things usually start at 3:30 am, and no one wants to be driving to the nearest 24 hour pharmacy at that hour).
After your child vomits, he usually feels better for a few minutes. Let the stomach settle for about 10 minutes after an episode, then offer him a very small amount of your ORS of choice. It is crucial that you not let him drink down multiple ounces at one time, as this will inevitably come back up. Start with a tablespoon, wait 10-15 minutes, then increase the amount. If he vomits again, start back at a tablespoon, or increase the time between sips. If you are breastfeeding, let the baby breast-feed for a minute or so every 10-15 minutes. If she is not tolerating the breast milk, switch to Pedialyte.
By following this method, your child should be able to maintain hydration. It has been studied extensively in foreign countries, where diarrheal illnesses cause death by dehydration more frequently than you want to imagine. ORS solution has saved many lives in these countries, and has been shown to work just as well as intravenous (IV) fluids when done correctly.
If your child is showing signs of dehydration like those above, he may need IV fluids in the emergency room. Although this will definitely help him feel better, the trip to the ER may not be the most fun. Always try oral hydration first. Your doctor can help guide you with the decision to get IV fluids.
Please note: Always take your child off milk or milk-based formula for at least 24 hours when he/she is vomiting. Vomiting makes us temporarily lactose-intolerant, so the lactose in these milk products will exacerbate the symptoms.
How long does vomiting last?
Vomiting with most minor illnesses will end within 6-12 hours. When children vomit for longer than that it is important for them to be seen, both to assess their hydration and to diagnose the cause of the vomiting.
How can vomiting be prevented?
A number of medicines are effective at preventing vomiting. Although effective, these medications are avoided as much as possible by pediatricians. They may have side effects, and they may mask underlying illness. The need for them are made on a case by case basis with your doctor.
When To Call the Doctor:
- Persistent vomiting lasting more than 24 hours
- Signs of dehydration
- Green or bloody vomit
- Vomiting in a baby under 6 months old
- Signs of abdominal PAIN with vomiting – the child may hold the stomach, bend over, or resist walking or movement
- Persistent fever with vomiting
- Vomiting in the mornings (with or without headache)
I hope this summary helps you the next time your child is throwing up. Remember to wash your hands and the toilet well, as these illnesses can be quite contagious!
