Flu and vomiting: Stomach flu or influenza?

The word ‘flu’ is used for both influenza and the stomach bugs that can cause vomiting and diarrhea. Learn the differences between flu and stomach flu.

Author: Kim Huston

Published: January 19, 2021 | Updated: March 12, 2025

Estimated reading time: 3 minutes

Flu is a word that is commonly used for influenza, an illness caused by a virus that causes symptoms in the nose, throat and lungs. Gastroenteritis, often called the “stomach flu,” is not the same virus that causes influenza. Learn the symptoms of both conditions to get your child the care they need.

What is stomach flu and how does it compare with the flu?

Gastroenteritis, often called stomach flu, can be caused by different viruses, including norovirus. Norovirus is one of the most common viruses to cause gastroenteritis. Norovirus is not the same as the flu virus that causes influenza. Norovirus symptoms can include:

  • Diarrhea
  • Nausea
  • Stomach pain
  • Vomiting

In children, nausea, vomiting and stomach pain are more common symptoms of gastroenteritis than influenza. However, those symptoms, including diarrhea, may appear in children with influenza, but not as often. The important thing to know is that if your child is experiencing vomiting and diarrhea but doesn’t have unrelenting fever , cough with body aches or other influenza symptoms, your child may have another viral or bacterial infection, not influenza.

Children usually develop gastroenteritis or norovirus symptoms 12 to 48 hours after exposure. Children usually experience gastroenteritis symptoms for one to four days. The only treatment for stomach bugs is supportive care, including drinking plenty of fluids to prevent dehydration, getting extra rest and eating a diet that is easy on the stomach. Avoiding caffeinated drinks, dairy and sugary drinks may help if your child experiences diarrhea and vomiting.

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Flu symptoms in kids — and how flu symptoms compare with a stomach bug

Children with influenza, often called the flu, tend to have more upper respiratory symptoms that usually appear out of nowhere. In the first few days of being sick with the flu, a child’s symptoms are usually more intense. Flu symptoms in children can include:

  • Persistent fever over 102 degrees for more than 48 hours
  • Body aches
  • Chills
  • Cough
  • Fatigue
  • Headache
  • Runny or stuffy nose
  • Sore throat
  • Sometimes diarrhea and vomiting

Flu symptoms in children can be treated with antiviral medication. If you think your child may have been exposed to the flu and/or develops a fever of 102 degrees for more than 24 hours, call your child’s pediatrician office to seek evaluation. Antivirals must be prescribed within 48 to 72 hours to be effective. This can help lessen the severity of the symptoms. The flu can be very serious in children — if your child has the flu and their symptoms worsen, it may warrant immediate medical care. Some of those symptoms include:

  • Fast breathing or trouble breathing
  • Bluish skin color
  • Not drinking enough fluids
  • Not waking up or not interacting
  • Being so irritable that the child does not want to be held
  • Flu-like symptoms improve but then return with fever and worse cough
  • Fever with a rash

Flu symptoms in children vs. stomach flu symptoms

Flu symptomsStomach Flu (Nororvirus) symptoms
FeverDiarrhea
CoughVomiting
Sore throatNausea
Runny or stuffy noseStomach pain
Body achesSometimes fever, headache and body aches
Headache 
Chills 
Fatigue 
Sometimes diarrhea and vomiting