Gastroenteritis and Dehydration in Children

The majority of acute gastroenteritis (AGE) is caused by viruses, including rotavirus, astrovirus, and calcivirus.  Rotavirus is the most common cause of AGE in children under the age of 2, and before the widespread use of the rotavirus vaccine, it accounted for half of the yearly AGE related hospitalizations.  Infections with rotavirus tend to peak between November and March. Norwalk or Noro virus is a type of calcivirus, and may be present throughout the year.  This virus is becoming well known due to its association with cruise ships.

All viruses that cause AGE tend to be quite contagious. Because they are spread by a fecal-oral route, outbreaks may occur in child care centers or after the ingestion of contaminated food such as shellfish, salads, or ice. Often, the food is contaminated by infected food handlers.

No matter the cause, the symptoms of AGE are always similar and include vomiting, diarrhea, abdominal cramping, decreased appetite, fever, headache and body aches.  The vomiting and diarrhea occur because the virus will invade the cells that line the small intestine, destroying its ability to retain fluid. 

In children, AGE typically begins with vomiting, later followed by diarrhea.  The symptoms may also vary each day, beginning as early as 12 hours after exposure or up to 4 days after.   It is possible to have as many as 20 episodes of vomiting and 20 episodes of diarrhea in one day.  The stool is usually loose and watery and may be odorless or foul-smelling.  Diarrhea may be normal or pale in color.  The entire episode of AGE may last for three to seven days. 

The most concerning complication of AGE in children is often dehydration.  Signs of dehydration include increased thirst, decreased urine output, dry mouth, fewer tears, and weight loss. If the level of dehydration becomes more severe, children may become cranky, with sunken eyes, and an increased heart and breathing rate. In extreme cases, the kidneys will stop working, the heart will not have enough fluid to pump correctly, the blood pressure will drop, and your child will go into shock.

In order to avoid these complications, it is important to make all efforts to keep your child hydrated during a bout of AGE.  This can be accomplished by offering small amounts of fluid, starting with a teaspoon at a time, over a specific time interval, such as 15 or 20 minutes.  As your child is able to tolerate these small amounts, you may gradually increase the amount and shorten the time interval.  Fluids such as Pedialyte or Gatorade are best to use because they contain salt and sugar, which helps to replace what it being lost by the vomiting and diarrhea.  Juice should be limited, as this may prolong diarrhea.  As your child can tolerate these clear fluids, you can advance to other liquids.  Breast-feeding as a means of rehydration appears to reduce the number, volume, and duration of stools.  Full-strength cow's milk and other nonhuman milk usually can be tolerated without problems and it is not necessary to dilute the milk or to substitute with lactose free formula or milk. 

When possible, it is recommended to restart an age-appropriate diet.  When diarrhea is the predominant symptom it has been shown that a relatively unrestricted diet will reduce stool output and the duration of illness.  Foods with high levels of fats and simple sugars are less well tolerated than those with complex carbohydrates, lean meats, yogurt, fruits, and vegetables.  The BRAT (bananas, rice, applesauce, toast) diet has been commonly recommended in the past, but feeding those foods alone becomes too restrictive and will not provide optimal nutrition. 

Because AGE is usually caused by a viral illness, it is not recommended to treat with antibiotics.  In addition, it is not recommended to give children antidiarrheal medications such as Immodium or Pepto-Bismol.  There is no substantial evidence that these medications will help to treat the illness and they may have serious side effects such as intestinal infections and liver failure.  There is some evidence to support the use of probiotics containing Lactobacillus during an episode of AGE.  The probiotics will help to repopulate the intestinal tract with its normal bacteria and may reduce the amount of stool output as well as decreasing the duration of illness.

Good hygiene practices are the best method for prevention of AGE.  This includes hand washing with warm, soapy water, especially after using the restroom and before meals.  Diaper changing areas should always be separated from food preparation areas.  When possible, you should keep your child away from others with AGE.  Try to prevent children from sharing food and eating utensils. 

Always remember to contact your pediatrician immediately if you ever have concerns about the length of illness or your child’s hydration status.