Officially called gastroenteritis, stomach flu is an infection of the digestive system — and is totally unrelated to the regular flu (influenza), which affects the respiratory system. Stomach flu is the second most common illness kids get, after respiratory infections like colds. Although unpleasant, stomach flu is usually not serious. It’s usually caused by viruses, but can also come from bacteria like salmonella and E. coli, as well as some parasites.
Stomach flu causes inflammation of a child’s stomach and digestive tract, usually triggering vomiting, diarrhea, and fever. “Babies and young children are especially prone to infection because their immune systems are still forming, so they haven’t yet built up the antibodies to fight off germs,” says Rita Steffen, MD, a pediatric gastroenterologist at the Cleveland Clinic in Cleveland, Ohio.
What Is Rotavirus?
Rotavirus is one type of bug that causes stomach flu and may make children sicker than other types (like adenovirus, enterovirus, astrovirus, and Norwalk virus). Until recently, most children had been infected with rotavirus once by age 2 and nearly all had had at least one bout by age 5, according to the Centers for Disease Control and Prevention (CDC). This particular bug is responsible for about 400,000 doctor visits and 200,000 emergency room trips in the U.S. every year. However, a new rotavirus vaccine may drastically decrease the number of cases once it becomes widely used.
Rotavirus between November and May, especially if he’s regularly exposed to lots of other kids in situations such as daycare or playgroups. Rotavirus is very contagious and can easily spread among kids and teachers. As with other viruses, there’s no quick treatment — you have to let the bug run its course. Keeping your child hydrated is the best way to help him feel better. In severe cases, a baby can become dehydrated in as little as six hours.
What Are the Main Symptoms of Stomach Flu?
The early signs of stomach flu can be easy to miss, especially in babies and toddlers. Be on the lookout for these red flags:
- Vomiting (more volume than usual everyday spit-up)
- Watery diarrhea
- Fussiness or irritability
- Acting more tired and sluggish than usual
- Decreased appetite
Older children may also complain of tummy cramps, muscle aches, and headaches. Symptoms generally set in one to three days after your kid’s been exposed to the bug, and can last anywhere from a day or two up to 10. The main risks from stomach flu are not from the symptoms themselves (although unpleasant), but the fact that upset stomach can make your child very dehydrated.
How Might a Child Catch Stomach Flu?
Stomach bugs are highly contagious. Playing with an infected child is the main way the virus spreads, since germs can live on toys and clothes for hours or even days. If the infection results from bacteria or parasites, your child may have consumed contaminated food or water (most likely while overseas or camping, for example).
What makes stomach flu particularly virulent is that children are contagious before they actually show any symptoms. Also, adults — with their heartier immune systems — may harbor the germs and pass them along without ever getting sick themselves.
So what can you do to stop the spread? “We can’t stress enough how important hand-washing is,” says Stanley Cohen, MD, a pediatric gastroenterologist at the Children’s Center for Digestive Health Care in Atlanta, Georgia. For a thorough scrub, use soap and warm water and rub your hands together for at least 15 to 20 seconds (sing “Happy Birthday” for a gauge of length); this helps prevent passing germs around your family.
It’s a good idea to wash not just after using the bathroom, but after coming home from public places like malls or movie theaters or after being around other kids on playdates, for example. Show your toddlers and preschoolers how to wash properly, and ask their childcare providers whether kids are required to clean their hands throughout the day (not just after using the bathroom and before meals).
Wiping down changing tables, potty seats, and toilet bowls with bleach may help, but not always. “Rotavirus can be quite resistant to cleaning products,” says David B. Nelson, MD, chair and professor of pediatrics at Georgetown University Hospital in Washington, D.C. “That’s why the vaccine has become so important in preventing illness.”
What to Know About the Rotavirus Vaccine
In 2006 the FDA approved RotaTeq, an oral rotavirus vaccine (that means no shots) for babies. There are a number of different strains of rotavirus, but four are responsible for most infections in the U.S., says Nelson. The vaccine specifically targets these four strains.
In studies, the vaccine prevented 74 percent of all stomach flu cases caused by rotavirus and 98 percent of severe ones. It also reduced hospitalizations by 96 percent. The CDC and American Academy of Pediatrics recommend babies receive the vaccine in three doses, at 2 months, 4 months, and 6 months. While the benefits of the vaccine are clear, as with any drug, there are a few things to keep in mind. Talk to your pediatrician if you have any concerns.
- There are slight side effects. Within a week of getting a dose, babies are slightly more likely to have mild, temporary diarrhea or vomiting than those who did not receive the vaccine.
- Your child can still get stomach flu down the road. The vaccine only prevents the four most common strains, so kids who have been vaccinated can still catch different types of rotavirus or other bugs that cause stomach flu. However, symptoms will likely be less severe in children who’ve been vaccinated, says Dr. Cohen.
- Be extra careful during post-vaccine diaper changes. “Healthy babies may shed the virus in their stool — even if they don’t exhibit any side effects,” says Dr. Cohen. Make sure you’re vigilant about hand-washing and diaper disposal in the first few days after each vaccine dose.
- It’s not right for all kids. The vaccine is not recommended for babies with suppressed immune systems because it can make them sick. It is also not approved for use in older babies or children — all three doses must be completed before your infant is 32 weeks (7 months) old.
When to Call the Doctor for Stomach Flu
If it’s your baby’s first bout with stomach flu, call the doctor right away. This way she can rule out bacterial infections, which may require treatment with antibiotics. If your doctor suspects that the infection is viral (as most are), she won’t prescribe any meds.
The pediatrician will likely ask you about fever. Most docs want to see babies under 3 months with rectal temperatures of 100.4 F. or higher. If your child is between 3 and 6 months, you should alert the doctor if your child has a rectal temperature of 101 F. or higher. If your child is older than 6 months, let the doctor know if your child has a rectal temperature of 103 F. or higher.
The doctor will likely also ask whether your child has any of these signs of dehydration:
- Fewer than 6 wet diapers a day for babies or 8 hours without peeing for older kids
- A sunken soft spot on top of baby’s head
- Few or no tears while crying
- Acting unusually sleepy, sluggish, or unresponsive
- Wrinkled skin
- Dry mouth or cracked lips
- Dizziness, headaches, or muscle pain in older kids
- Urine that’s dark yellow (instead of light or clear)
- Weight loss
If a child of any age seems severely dehydrated, call the doctor right away. The child may need to go to the hospital to get rehydrated through IV fluids.
You should also let your doctor know if your child has been throwing up for more than two days, has diarrhea for more than four days, or has blood in his stool (which can be a sign of a bacterial infection or other digestive problems).
How to Help Your Child Recover from Stomach Flu
Unfortunately, there is no specific treatment for viral stomach flu; it just has to run its course.
But replacing lost fluids and nutrients will help your child feel better more quickly and prevent the bug from getting worse. Here’s what to do:
- Keep up the fluids.
For breastfed or formula-fed babies: Let your infant’s belly rest for 15 to 20 minutes after a bout of vomiting or diarrhea, and then try nursing or bottle feeding again. “Breast milk is actually well tolerated by sick babies; plus the antibodies in it can help strengthen their immune systems,” says Dr. Cohen.
For toddlers and older kids: Ask your doctor about rehydrating drinks, like Pedialyte, which are absorbed better than water. These solutions replenish the crucial salts and sugars lost when your child is throwing up or has diarrhea. It’s a good idea to keep some in the medicine cabinet for just-in-case purposes.
Your child may have a hard time keeping down fluids at first. But sticking to small, frequent doses (try a teaspoon every couple of minutes) may help rebalance fluid and salt levels in the body, which can actually help stop vomiting over time.
- Get back to a normal diet. Don’t worry about food while your child is still throwing up. But once his stomach calms down, start him on bland, easy-to-digest stuff (like toast, rice, bananas, and potatoes). Most experts agree that children should resume eating everyday foods (like whole-grain breads and cereals, meats, fruits, and veggies) once they can keep food down. Also, avoid fatty and sugary foods, which are harder to digest and may make diarrhea worse.
- Treat the fever. If a higher-than-normal temperature is making your child uncomfortable, you can use acetaminophen or ibuprofen to bring his temperature down. This may help relieve other aches and pains too.
- Let him rest. Your child will probably be sleeping and napping more than usual, which is normal. But if your baby or toddler has been asleep more than 4 hours (and has been having diarrhea or vomiting), you may want to wake him up to offer fluids. “Remember that infants can become dehydrated more quickly than older kids,” says Dr. Steffen. “Use common sense, like watching for signs of dehydration.”
What Medications Are Safe for Stomach Flu?
Other than using acetaminophen or ibuprofen to treat a child’s fever, medications are usually not recommended for treating viral stomach flu (antibiotics may help treat bacteria-triggered cases, but these are much less common in babies and young children).
In fact, most doctors will tell you to avoid using over-the-counter anti-diarrheal medications (like Imodium). These drugs work by slowing down the digestive system, which may actually make it harder for your child to fight off a stomach bug. Children should not receive tummy soothers like Pepto-Bismol either. The drug contains aspirin-like ingredients that may cause Reye’s syndrome, a very rare but potentially fatal disease, in children and teenagers.
When/What to Start Eating After Stomach Flu
While your kid’s having trouble keeping food down, stick to rehydrating fluids. Avoid food for a couple of hours after your child throws up, then slowly work in bland foods like toast or rice.
Once these fluids and foods stay down, most doctors recommend that children resume eating everyday foods like chicken, veggies, and rice right away. “A drastic change to your child’s regular diet can actually trigger more diarrhea and make him feel worse,” says Dr. Steffen. And doctors now believe the old stomach flu standby — the BRAT (bananas, rice, applesauce, and toast) diet — is too low in protein, fat, and other key nutrients. Try to avoid sugary or overly fatty foods and drinks, which are harder to digest and may upset your kid’s tummy further.
How Long Will Stomach Flu Last?
Depending on the virus and your child’s immune system, the stomach flu can last anywhere from just a day or two to around 10 days. “Children tend to throw up for just the first day or two, but diarrhea can last more than a week,” says Dr. Nelson.
Stomach flu can also make your child prone to short-term and completely reversible lactose intolerance (the inability to digest an enzyme in milk and dairy products), which may be responsible for lingering diarrhea in toddlers and older kids. “If milk seems to make diarrhea worse, ask your pediatrician what to feed your child,” says Dr. Nelson. You may want to try yogurt instead, which is easier to digest, and return to milk a day or two after.
If your child is still throwing up after two days or has diarrhea for more than four days, check in with the doctor again. She may want to do additional tests to see if a different type of infection or condition might be to blame.