Stomach Flu: What Gastroenteritis Really Is

Mary Lucas, RN

Medically reviewed by Mary Lucas, RN

Written by Our Editorial Team

Last updated 11/17/2020

It sounds fairly  benign, the stomach flu. But if you’ve had it, you know — having this bug is far from dull. 

Between the nausea and numerous trips to the bathroom, having the stomach flu can be exhausting. 

The good news is: it will be over soon. 

The illness doesn’t typically stay round long. But in the meantime, having some idea of what to expect and how to ease your symptoms can make its stay a bit more tolerable. 

What Is the “Stomach Flu?”

Viral gastroenteritis! Now you know why we just call it the “stomach flu.” Gastroenteritis is common and is seen around the world, accounting for 200,000 deaths every year, according to the Centers of Disease Control. However, most cases are not fatal.

The stomach flu can be caused by several different types of viruses: norovirus, rotavirus, adenovirus and astroviruses. 

These viruses may be spread through contaminated food and water, contact with people who are infected, surfaces and potentially in the air.

Norovirus accounts for about half of viral gastroenteritis cases. In fact, it’s the most common cause. 

It’s a resilient virus because it’s resistant to freezing, heat and many disinfecting products. 

It’s a common cause of stomach flu outbreaks in crowded conditions like schools, nursing homes, sports teams and the like.

Gastroenteritis is affectionately referred to as the “stomach flu” because the worst symptoms are vomiting and diarrhea. It’s not a good time. 

What The “Stomach Flu” Isn’t

Despite being called the stomach flu, viral gastroenteritis is not related to the influenza viruses. It is not “the flu.” 

And while people may refer to just about any upset stomach condition as a “stomach bug,” the stomach flu is not caused by food poisoning, pregnancy or any of the other conditions that can lead to nausea. 

And even though it’s called the “stomach” flu, it is actually not an infection of the stomach, but rather of the intestines.

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Stomach Flu Symptoms 

The symptoms of gastroenteritis are pretty basic: nausea and vomiting, diarrhea and stomach or abdominal pain. 

These symptoms can occur many times throughout the day. According to the CDC they begin within 12 to 48 hours after being exposed to the virus, but they may also start as early as four hours after exposure to the virus.

In addition to these upset stomach symptoms, you may experience headache, fatigue, body aches, joint stiffness, muscle pain, weight loss and chills with the stomach flu.

Stomach Flu Treatment 

As with the common cold (also caused by a virus), there is no “cure” for the stomach flu. 

Instead, treatment is focused on managing your symptoms. The symptoms typically resolve within a few days. 

So while unpleasant, it doesn't last forever.

Because you may be vomiting and having diarrhea, it’s very important to stay hydrated. 

Drink clear fluids as much as possible — including water — and if your  stomach is too upset for that, consider ice chips or cubes. 

Sports drinks may be tempting, but these high sugar beverages are not good at preventing dehydration. 

However, older children and adults can have Gatorade®. If you need some flavor in your clear liquids, try Pedialyte® or other rehydration solution to help restore electrolytes. 

When your appetite returns, eat small portions of bland, easy to digest foods such as saltine crackers, bananas and plain rice.

If you’re tempted to try medications to treat your symptoms, over-the-counter solutions such as Imodium and Pepto-Bismol® may ease your stomach discomfort. 

Watch for signs of dehydration. 

If you experience dizziness upon standing, reduced  urination or severely dry mouth and throat, you should  call your healthcare provider or seek immediate medical attention.

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Preventing the stomach flu, like preventing most viral infections, involves good hygiene practices. 

Wash your hands thoroughly and frequently throughout the day. If you come in contact with an infected person, wash any potentially contaminated clothing and surfaces. 

If you yourself are sick, stay home and away from other people to prevent the spread of the unpleasant illness.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

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