What are the symptoms of the stomach flu?

Answer: The main symptoms of the viral gastroenteritis are vomiting and/or diarrhea.

"Stomach flu" is just a nickname. The viruses that cause the "stomach flu" are not related to influenza, the real flu. The symptoms of viral gastroenteritis1 are vomiting and diarrhea. Sometimes lucky people only have diarrhea and never vomit (or just vomit once). The vomiting phase usually only lasts from 1-3 days (although it seems like an eternity). The diarrhea may continue for 1-2 weeks. There may also be headache, fever, chills, and abdominal pain. Usually the vomiting comes first and then the diarrhea; however, I have seen cases where the diarrhea precedes the vomiting. My one year old just had a tummy bug where he had diarrhea one day, vomiting the next day, and then more diarrhea the next day. Often there is a delay between the vomiting and diarrhea. Your child may feel fine for 24 hours after vomiting and then the diarrhea starts. My older son had a stomach bug in January 2012. He vomited 3 times on Sunday, had no symptoms on Monday. On Tuesday afternoon (48 hours after he was done vomiting) he had one explosive bout of diarrhea. People can also have a relapse where they feel better for a day and then get sick again. It is common for children to vomit again 2 days after the first time. Occasionally, a person will vomit one last time 1 week later! Sometimes a stomach virus just causes diarrhea. My son recently had an illness where he had 2-3 diarrhea explosions each day for 6 days. He had no other symptoms and didn't feel sick at all. Occasionally, babies and toddlers won’t get the vomiting. They will have only the diarrhea and just do not eat much for a few days. Also, a particular gastroenteritis virus can affect people differently. For example, you may have several bouts of vomiting but no diarrhea. Whereas your spouse or child might have vomiting and diarrhea so severely that they have to go to the ER for an IV. Make sure you are cleaning with a product that kills norovirus like the Clorox® Hydrogen Peroxide Spray

A stomach bug ran through my house in January/February 2012. My 7 year old son, Jon, got it first. He threw up 3 times on Sunday. He had no symptoms on Monday but hardly ate anything. Tuesday afternoon he complained of bad tummy pains and had 1 bout of explosive diarrhea. Then he was fine. Since Jon got everything in the toilet and I kept him quarantined for 2 days, I thought we all might escape it. Unfortunately, the following Saturday ( 7 days later), my baby (16 months) Michael got sick. He had 3 bouts of liquid diarrhea on Saturday evening. He vomited in the middle of the night. Then he had no symptoms on Sunday but didn't eat much. I thought he was getting over it because there were no symptoms for 18 hours. Unfortunately, he was up all night Sunday night with vomiting (4 times) and diarrhea. His diarrhea lasted 10 days. Because the symptoms can take an intermission, it is important to keep your kids home from school or day care for a few days to make sure they are over the illness. If they are not eating normally, they are not well. After being vomited on by my baby, there was little hope for me. I got sick Monday night. It wasn't too bad for me. I just threw up 2 times and then felt much better.

By the way, if you are looking for a fabulous thermometer, I have had this Exergen Temporal Artery Thermometer

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Although primarily a respiratory illnesses, influenza can cause vomiting. My son, Michael, had influenza A in 2013 when he was 2. He vomited a few times. I caught it from him but I did not vomit. My neighbor recently had influenza A in 2014. He said that he threw up 5 times. His wife caught it from him but she never threw up. I have been hearing stories lately (in 2014) that the H1N1 strain is causing some adults to vomit more than the flu usually does. I don't like that one bit.


Frequently strep throat masquerades as a stomach virus--especially if your child is too young to tell you his/her throat hurts. Strep throat can cause vomiting. As I am writing this, my 4.5 year old daughter is upstairs in bed with strep throat. The illness started on Thursday (April 26, 2012) when she had a low fever of 100.5 and spent most of the day on the couch. I asked her if her throat hurt and she said "no". I asked her if it hurt when she swallowed and she said "no". But still, it looked to me like she was having difficulty swallowing. She ate nothing all day would only drink water. At 1am she woke up and vomited in her bed (multiple heaves). She also vomited again at 9am on Friday. Friday afternoon I was pretty sure she had a sore throat so I took her to the doctor. The throat culture confirmed that she had strep. I was surprised that her fever never got over 100.5 and I wasn't giving her any fever reducing medicine (because she refused to take it). I was also surprised because she had a little cough and significant nasal congestion (the mucous was unquestionably green). I had read that strep throat usually doesn't come with other cold symptoms . It is Monday now and she has hardly eaten any food or drink other than water since Thursday morning. When my son was 3, he had a bad case of strep throat. He also vomited 2 times. So, strep throat can definitely affect a child's tummy. If untreated, strep throat can spread all the way through the intestinal tract. When my son was 3, his strep test came back as a false negative. Without an antibiotic, his illness progressed to Scarlet Fever. He had a red rash all over his body AND he had burning diarrhea. It was his burning bottom that they swabbed and finally got a positive strep test. So, if your child has a fever and sore throat along with vomiting, they need to be checked for strep throat. Be aware that baby /toddler or child younger than 5 might not tell you that his/her throat hurts. One viewer wrote to me and told me that her kids don't even get a fever with strep...they just start throwing up.


Some people, like my sister, have had heartburn so bad that they actually throw up. If this happens to you, definitely see a doctor about Gastroesophageal reflux disease (GERD).


If a person has had a cold and then gets a fever, headache, and vomiting, have them checked for pneumonia. Some children have vomiting and fever as the main symptoms of pneumonia.

Mucous, coughing, and ear infections

Other illnesses can cause person to vomit that are not the stomach flu. For example, young children who have a bad cold and can't blow their nose may get a tummy ache from all of the mucous that they are swallowing. When my 1-year old had a bad respiratory infection, she threw up once either from gagging/choking on mucous or because the mucous made her nauseated. When she was 7, my daughter had a terrible cold producing a ton of mucous. Even though she blew her nose constantly, she woke up one night gagging on mucous and proceeded to dry heave for 45 minutes. No doubt her tummy was upset from being full of mucous that dripped down while she was sleeping. My daughter also vomited twice when she had an ear infection when she was 3 years old. My 2 year old nephew also vomits occasionally when he has an ear infection. I recently had a respiratory illness that caused me to cough so much that I threw up. So, if your child has another illness and they vomit, don't automatically assume that they also have the stomach flu. It is possible but hopefully they don't.

Laughing, choking, bouncing, spinning, crying

Too much laughing can also occasionally cause a child to vomit. I was tickling my 1 year old too much recently and he threw up a little on the carpet. Also, my 4 year old daughter was laughing so hard at her brother while trying to take a sip of water. She choked a little and threw up everywhere. I was surprised that she threw up with multiple heaves. Once a person starts vomiting, it is hard to stop. My older son threw such a bad screaming and crying fit one time that he threw up everywhere. Once when my niece was visiting, she ate a big hamburger and then immediately started bouncing in our blow up bouncer. She came out green about 15 minutes later. Her family left but she vomited multiple times on the car ride home.

Food Allergy

Sometimes the first sign of a food allergy is vomiting after eating something new. My cousin's son has lots of food allergy. When he was 10 months old, he tried oatmeal and vomited 10 times in the 3 hours afterward. He was very sick.

Eating too many sweets

Eating too much junk (cookies, candy, cake, sugar) can give anyone a stomachache and may make them vomit. I had a bad experience when I was 10 years old. I ate half a bag of oreos and got very sick. So, if you let your child eat 15 pieces of Halloween candy today, and they are up vomiting tonight, the candy is probably the cause.

Carbon Monoxide Poisoning

Carbon monoxide is an odorless gas that binds to the hemoglobin in your blood in place of the oxygen that your body needs. It is deadly. I was contacted by someone who thought they had food poisoning. He and a friend were on a 2 hour car ride. They stopped and ate at a gas station. An hour later they both had a terrible headache and were nauseated. One started vomiting violently. The other managed to not vomit. They had body aches. I thought the problem was probably the food that they shared at the gas station. However, I was wrong. It was carbon monoxide. They were driving in an old car with the rear view window rolled down. The exhaust went right into the car on the trip. If your illness starts in a car or on a motor boat, consider carbon monoxide. Everyone should have a carbon monoxide detector in their home.

Food Poisoning can also make you throw up. I have pages of this site devoted to food poisoning so please read them for more information.

This is by no means a complete list of everything that could make a person throw up. This is just some of the common things that I have personal experience with.

If you are experiencing vomiting with the additional symptoms of dark urine, clay-colored bowel movements, and/or jaundice--call your doctor immediately. These are symptoms of hepatitis, not viral gastroenteritis. Hepatitis is much more serious, so get to the doctor.

Appendicitis is often misdiagnosed as gastroenteritis. Unfortunately, if the appendix bursts, it can be deadly. Symptoms of appendicitis include, nausea, vomiting, fever, and sharp pain in the lower right abdomen. A friend of mine had her appendix rupture one night recently. It started with cramping like she was getting sick. Then she started vomiting. She thought she had a stomach bug. Then the pain was so bad in her right side that she couldn't stand up. She couldn't even straighten her right leg. Then she went to the hospital, thank heavens. Since young children often can't tell you where it hurts, about 80% of of children under age 4 with appendicitis end up with their appendix bursting. For more information about appendicitis visit this Johns Hopkins website. I wish I could give you more information about distinguishing between appendicitis and gastroenteritis but even physicians have a very difficult time differentiating.

Please keep reading this website for information on more vomiting illnesses including bacterial gastroenteritis, parasitic gastroenteritis, and food poisoning.

--Annie Pryor, Ph.D.

Viewer Comments:

Strep Throat Disguised as Stomach Bug

Both of my children have suffered from what looked like stomach viruses but turned out to be strep throat --even though they didn't report a sore throat or have a fever. We found out only because I take them to the doctor if they are still throwing up after 24 hours. Just last spring I told my friend to have her daughter tested for strep when she had a "stomach virus" that came and went for days and days -- it was strep.


Thank you for your website - it was easy to understand, funny, empathetic, and exactly what I needed as I am lying in bed. My symptoms started on Monday. But what I thought was interesting was that my boyfriend had night sweats Sunday night and I woke him up to see if he was feverish. He was clammy, but no fever. The next day I went to work and immediately felt body aches and a sore stomach. I went home and slept. I felt better on Tuesday, and went to work. Then I went back home because I had diarrhea. It is now Thursday and I haven't been able to eat much except for applesauce. My stomach feels hungry (above the bellybutton), but the intestines (below) feels sore when I press on it. It is like a weird sore...as if it's raw and raked over. My poop has been mostly water with some greenish/brownish poop (sorry - so gross). But it doesn't spread in the toilet bowl like normal diarrhea does...I have NEVER been this sick for so long with a fever peaking at 102. I have no idea where I caught this bug and am hoping it will go away by tmrw bc i am STARVING! I am also am obsessive about washing my hands when I come inside from outside. I learned it from my mom. You have to! Thanks for your website. It made me feel better.


1. http://www.mayoclinic.com/health/viral-gastroenteritis/DS00085/DSECTION=symptoms

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Return to stomach flu FAQs


Taking medications, vitamins, activated charcoal, or probiotics on an empty stomach can cause vomiting.

Empty Stomach

There are other things besides stomach bugs that cause vomiting. For example, if you child had a cold and then develops a fever with or without vomiting, you need to get them checked for an ear infection and pneumonia.

Other Causes of Vomiting