Vomiting and Diarrhea in Children

Few things are harder than watching your child deal with a stomach illness. Vomiting and diarrhea are some of the most common reasons parents reach out to us, and they can feel alarming when they happen, especially in younger children.

Most of the time, these symptoms are caused by a stomach virus and will get better with rest, fluids, and a little patience. But there are times when they signal something that needs medical attention.

This page will help you understand what is likely going on, how to keep your child comfortable at home, and when it is time to call our clinic or head to the emergency room.

What Causes Vomiting and Diarrhea in Children

The most common culprit is viral gastroenteritis, which most people call the stomach flu. Despite that nickname, it has nothing to do with the influenza virus, but is often caused by norovirus. It spreads easily among children, especially in daycares and schools. It will typically clear on its own within a few days to a week.

Other possible causes include:

Bacterial infections from food poisoning or contaminated food and water
Food protein reactions, such as cow's milk protein allergy in infants or FPIES (food protein-induced enterocolitis syndrome) in infants and toddlers
Strep throat, which can sometimes cause vomiting, fever, sore throat, and stomach pain
Urinary tract infections, especially in infants, which can present as vomiting and fever without diarrhea
Toddler’s diarrhea, often caused by eating sugar or changes in habits
Traveler's diarrhea from contaminated water or food while traveling
Antibiotic-associated diarrhea from disruption of the gut's normal bacteria, including C. diff
Parasitic infections like Giardia, which is more common in young children in childcare settings
Ongoing conditions like inflammatory bowel disease (IBD) or celiac disease, in cases where symptoms are chronic rather than sudden

Vomiting can also be a sign of something unrelated to the digestive system. Severe headaches with vomiting, recent head trauma, or vomiting without diarrhea alongside a high fever can sometimes point to a different underlying issue. More on those red flags below.

The rotavirus vaccine, given to infants, is very effective at preventing severe vomiting, diarrhea, and dehydration.

Should I Care for My Child at Home, Call the Clinic, or Go to the ER?

Use this guide to help you decide. When in doubt, give us a call. We would rather hear from you than have you worry alone.

Home Care
You may consider caring for your child at home if they are:

Six months or older
Still urinating regularly
Able to keep down small amounts of fluid
Alert and responsive, without extreme fussiness

Contact the Clinic
We want to check your child within the next day if you notice:

Vomiting, diarrhea, or fever in a child younger than 3 months
Small amounts of blood in the diarrhea or vomit, but your child is alert
Vomiting that might be green-tinted (bilious)
Symptoms are not improving after a few days, or are getting worse
Your child can’t keep down fluids
Your child is under 6 months old
Your child has a chronic condition like diabetes or IBD

Seek Emergency Care
Call 911 or go to the nearest ER if your child:

Is unconscious or extremely difficult to wake up
Has bright green or yellow (bilious) vomit, which may indicate a serious blockage
Has large amounts of blood in vomit (bright red or resembling coffee grounds) or large amounts of blood in stool
Has severe abdominal pain that is constant, getting worse, or accompanied by a noticeably swollen belly
Signs of dehydration: can’t keep down fluids, has not urinated in 8 to 10 hours (or fewer than 3 wet diapers in 24 hours for infants), has no tears when crying, has a very dry mouth, or has sunken eyes or a sunken soft spot on the head for infants
Recently had a head injury and is now vomiting
Has a severe headache along with vomiting

Your child's age

Younger children, especially infants, can become dehydrated more quickly than older kids. Here is what to keep in mind by age group:

Newborns and young infants (under 3 months): Contact our clinic or the ER for any vomiting, diarrhea, or fever. Babies this age need to be evaluated promptly.
Infants (3 to 12 months): They should be seen if they have persistent vomiting, signs of dehydration, blood in stool, or poor feeding. Keep in mind that breastfed babies can have widely varying stool patterns. If your baby seems to have more watery and more frequent stools than usual, that is the key sign of diarrhea, not a single loose stool.
Toddlers and young children: Vomiting and diarrhea are common in daycare settings. Young children cannot always describe or locate their pain, so watch their behavior closely.
School-age children and teens: Older kids are better able to tell you how they feel. Chronic bloody diarrhea in this age group, especially with weight loss, should be evaluated for IBD.

Watch for dehydration

Dehydration is the biggest concern when a child is vomiting or has diarrhea. Dehydration can develop quickly, especially in younger children. Know the warning signs:

No urine in 8 to 10 hours (or fewer than 3 wet diapers in 24 hours for infants)
No tears when crying
Dry or sticky mouth
Sunken eyes
Sunken soft spot (fontanelle) on the head in infants
Extreme lethargy, meaning your child is very difficult to arouse, floppy, or unresponsive

Tired and wanting to rest is normal with a stomach illness. True lethargy is when your child doesn’t respond to stimulation and is difficult to wake up or arouse.

Signs that might mean something other than a stomach virus

Not all vomiting and diarrhea comes from a stomach bug. A few things to keep in mind:

Diabetic ketoacidosis (DKA): If your child seems very sick with vomiting but also has increased thirst, frequent urination, or a sweet or fruity-smelling breath, call us right away or go to the ER. DKA can be the first sign of Type 1 diabetes and requires emergency care.
Appendicitis: Suspect this if your child has severe, constant abdominal pain that starts near the belly button and moves to the lower right side.
Intussusception: In toddlers, watch for episodes of intense abdominal cramping with bloody or mucousy stools. This is a bowel emergency that requires immediate care.
Pyloric stenosis: In infants between 3 and 8 weeks of age, persistent forceful (projectile) vomiting after every feeding can be a sign of pyloric stenosis. This is different from normal infant spit-up. Contact us or the ER right away.

When your child is on antibiotics

Some antibiotics, especially amoxicillin-clavulanate (Augmentin), commonly cause diarrhea. If your child starts diarrhea while on antibiotics, adding a probiotic or yogurt with live cultures can help.

Ask our team for a recommendation. In some cases, a C. diff infection can develop after antibiotics. If diarrhea is severe or persistent, let us know.

At-home Care for Vomiting and Diarrhea

Hydration. This is the most important thing you can do. Start with about one teaspoon of water or Pedialyte every 5 minutes and gradually increase if your child keeps it down. Avoid sugary drinks (juice, sports drinks, and soda) as they can make diarrhea worse. If your child vomits, wait 15 to 30 minutes before offering fluids again.
Feeding. Do not force your child to eat if they are not hungry. When they are ready, offer bland foods like plain rice, grilled chicken, toast, and bananas. Avoid greasy or high-fat foods.
Dairy. Stomach viruses can temporarily reduce the enzyme needed to digest lactose, so some children feel better avoiding milk products for a few days. That said, if dairy is the only thing your child will take, a little is better than nothing.
Breastfeeding. Keep nursing. Breast milk provides excellent hydration and antibodies, and you should continue as long as your baby is tolerating it.
Medications. Use acetaminophen (Tylenol) for pain or fever. Avoid ibuprofen, which can irritate the stomach. Never give anti-diarrheal medications like Imodium to children.
Probiotics. For children 2 years and older, probiotics or yogurt with live cultures may help shorten recovery. Ask our team for a recommendation.
Hygiene and preventing spread. Wash hands thoroughly with soap and water; hand sanitizer is less effective against norovirus. Do not share cups, utensils, or pacifiers. Disinfect bathroom surfaces, and keep your child home until they have been symptom-free for at least 24 hours.