Acute gastroenteritis (AGE) is a seasonal disease with peaks in the summer, when it is caused by a family of viruses known as the enteroviruses, and the winter, when it is caused by either rotavirus or Norwalk-like viruses. The hallmarks of gastroenteritis are, you probably guessed it already, vomiting and diarrhea. The vomiting and diarrhea are often accompanied by fever, and about 10 percent of cases of rotavirus-induced AGE are accompanied by an ear infection. In diarrhea caused by viral infections, blood is relatively uncommon, whereas in diarrhea caused by the bacteria Salmonella and Shigella blood is expected. This is why your pediatrician will often ask if you have noticed any blood in the diarrhea. AGE is spread via poor hygiene (i.e., poor handwashing after using the bathroom), and the viruses can live on contaminated surfaces (as people often discover on cruise ships). In the US, children tend to experience approximately 0.9 episodes per year of AGE unless they are in daycare when the incidence rate jumps to 4.5 episodes per year. The major potential complication of AGE is dehydration requiring intravenous fluid treatment.
“My child has the stomach flu…what can I do for him?” This has become a very frequently asked question of late. The answer is surprisingly low tech. For children who have diarrhea but have been spared the vomiting component of AGE the answer is simply to provide enough fluids to replace the fluid lost in the diarrhea. Acceptable choices for replacement fluids are Pedialyte, Powerade/Gatorade or even ginger ale or Sprite. Water is acceptable up to a point as the body looses in the diarrhea. If you simply give water, the salts are not replaced and the body becomes salt-depleted. This can actually make your child sicker. Another type of fluid not to give for diarrhea is apple juice as the juice can actually worsen the diarrhea due to its high concentration of sugar. Often the pediatrician will recommend something known as the BRAT diet (Bananas, Rice, Apples, Toast) as these foods tend to be somewhat binding and may help make the stool less liquid. Finally, children with severe diarrhea can become temporarily lactose intolerant. As such, the pediatrician will often recommend avoiding dairy products or switching infants to a soy-based formula such as Isomil DF.
Vomiting is a somewhat more difficult issue to deal with than is diarrhea. The first thing to do for vomiting is to give the stomach a rest. Wait at least 30–45 minutes after your child vomits before attempting to re-feed him or her. This allows some of the inflammation in the stomach to die down, lessening the chances of further vomiting. The next thing to do is to start giving your child clear fluids such as Pedialyte, Gatorade, ginger ale, Sprite etc. in relatively small amounts. I often recommend starting with 1–2 ounces every 30–45 minutes. Smaller volumes tend to be less irritating to the stomach and therefore allow you to replace lost fluid without inducing further vomiting. If one ounce is still too much then I generally recommend decreasing to a teaspoon of fluid every 10–15 minutes. In most cases this is sufficient to provide fluid to the body to stave off dehydration without causing any more vomiting, but when it fails you need to call your pediatrician to determine if it is necessary to bring your child to the Emergency Department for intravenous fluids. This is relatively rare, but unfortunately sometimes necessary. Finally, if your child is having persistent vomiting without any diarrhea you should always consult your pediatrician.
AGE can last anywhere from 24 hours to a week. The vomiting component rarely lasts more than 2–3 days but the diarrhea can linger for longer. The key is always to encourage your child to drink to prevent dehydration. If you see signs of dehydration such as dry mouth, infrequent urination or lethargy you should call your pediatrician to discuss any necessary treatments.
By Robert Jawetz, MD, FAAP
Dr. Robert Jawetz is a pediatrician at Tenafly Pediatrics.