A Overview of the 24-Hour Stomach Flu

What You Should Know About Gastroenteritis

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If you have ever come down with the stomach flu and have experienced episodes of crushing nausea, vomiting, and diarrhea, someone probably told you that it's just a "24-hour bug."

Is there really such a thing? Can a stomach bug actually slip through your system as fast as that, leaving behind only a vague memory of the illness?

This article explains the symptoms, causes, and treatment of the stomach flu.

Understanding Stomach Flu

When describing a stomach bug, the word "flu" is not exactly correct. In purely medical terms, the flu (influenza) is a common viral infection that mainly affects the respiratory system. You usually have symptoms such as:

On the other hand, the stomach flu is more accurately referred to as gastroenteritis. Unlike influenza, gastroenteritis can be triggered by any number of disease-causing pathogens including:

It is commonly associated with the rotavirus in children and either the norovirus or Campylobacter bacteria in adults.

Here's a brief look at the main differences between stomach flu and seasonal flu.

African-american woman holds stomach - stock photo

Catherine McQueen / Getty Images

Stomach Flu
  • Also known as gastroenteritis or infectious diarrhea

  • Gastrointestinal infection that can be caused by a virus, bacterium, or parasite

  • Spreads through person-to-person contact, contaminated food or water, or, in the case of parasites, contact with infected feces

  • Symptoms include vomiting, diarrhea, fever, and stomach pain

  • Vomiting usually lasts 24 hours; diarrhea may continue for several days

  • Also known as seasonal influenza

  • Upper respiratory infection caused by a virus

  • Spreads by dissemination of virus in droplets spewed into air when an infected person sneezes or coughs; particles can travel as far as six feet

  • Symptoms include fever, chills, muscle aches, cough, and congestion

  • May last from two to 10 days

  • May be prevented with a yearly vaccine

Clearly, because lots of things can cause stomach flu, it may be overly optimistic to suggest that it will go away in 24 hours. It may do so, but it can also take up to 10 days for some to fully recover.

Stomach flu can last from 24 hours to over a week, depending on what caused it.

Stomach Flu Symptoms

Gastroenteritis, also known as infectious diarrhea, is characterized by the inflammation of the stomach and gastrointestinal tract.

It can lead to

  • Vomiting
  • Diarrhea
  • Fever
  • Abdominal distress (pain, cramps)

In general, stomach flu appears suddenly. It hits hard. Then it gets better once the symptoms decrease.


The most common causes of stomach flu include:

  • Viruses such as rotavirus, norovirus, adenovirus, and astrovirus are known to cause viral gastroenteritis. These represent around 70% of stomach flu cases in children, especially the rotavirus. The norovirus represents around 60% of all cases in the United States. The viruses are extremely contagious and easily passed from person to person. They are also passed indirectly through contaminated food and water.
  • Bacterial causes include Campylobacter jejuni, Escherichia coli, Salmonella, Shigella, and Clostridium difficile. Bacteria-associated gastroenteritis is primarily related to something you ate. Of the possible bacterial causes, Campylobacter strains account for around one-third of all cases. Many of these infections are transmitted through contaminated poultry or other tainted foods, including meat, produce, and dairy products.
  • Parasites are less common causes of gastroenteritis but still account for around 3% of all cases in children. The primary culprit is Giardia lamblia. It's spread through contaminated food, water, or by the fecal-oral route (poor hygiene).

Handwashing after using the restroom and practicing good hygiene helps prevent the transmission of stomach flu.


While many illnesses tend to be transmitted in the air, the bacteria, viruses, and parasites that can cause gastroenteritis tend to be transmitted by:

  • Contaminated food
  • Contaminated water
  • Person-to-person contact


how to treat the stomach flu

​Verywell / Emily Roberts

Symptoms of gastroenteritis are usually acute and go away on their own without the need for a healthcare provider's visit. The main focus of treatment is the prevention of dehydration due to the severe loss of fluids.

Supportive therapies may include:

  • Rehydration with water or electrolyte-rich sports drinks (sodas and any fruit juice high in simple sugar should be avoided)
  • A BRAT diet (consisting of banana, rice, apple, and toast) to ease a queasy stomach and stop diarrhea
  • Anti-nausea medicines like Reglan (metoclopramide) to reduce the incidence of vomiting and lessen the risk of dehydration
  • Tylenol (acetaminophen) to relieve fever with fewer side effects and less stomach upset

When to Call a Healthcare Provider

Call your healthcare provider immediately or go to the emergency room if the following occurs:

  • You have vomiting or diarrhea that continues for more than 24 hours
  • You experience violent vomiting
  • You have blood in your vomit
  • You are having trouble keeping fluids down
  • You are experiencing signs of severe dehydration

Severe dehydration symptoms include dizziness, weakness, confusion, fainting, or fever over 101 degrees F .


Stomach flu is transmitted by contaminated food or water. It's also transmitted through person-to-person contact. It is not the same as the flu, or influenza.

Common symptoms of the stomach flu include fever, abdominal distress, nausea, vomiting, and diarrhea, Sometimes, stomach flu may go away after 24 hours. But it may take up to 10 days before you fully recover.

Frequently Asked Questions

  • How long does gastroenteritis last?

    Despite the nickname "24-hour stomach flu," most cases of gastroenteritis last longer than a day and night. Depending on the cause, a so-called stomach bug could persist for up to 10 days.

  • What happens inside your body when you have a stomach bug?

    This depends on what's responsible for the illness. That said, in most cases, a virus, bacterium, or other microbe invades either the small or large intestine, producing toxins that cause vomiting, diarrhea, inflammation, and other symptoms.

  • What is the most common cause of gastroenteritis?

    Norovirus causes the majority of acute cases of gastroenteritis in the United States. Around 80% of norovirus infections occur between November and April. Babies between 6 months and 18 months of age are especially susceptible.

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6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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