Flu or a stomach virus? How to tell the difference

Does your child have a fever? Are they throwing up? What about diarrhea? You may be wondering if it is the flu or a stomach virus.

Norton Children’s Medical Group

Our pediatricians offer care for children with the flu or stomach virus at more than 25 convenient locations across Kentucky and Southern Indiana.

Does your child have a fever? Are they throwing up? What about diarrhea? You may be wondering if it is the flu or a stomach virus. 

Sometimes what we call the flu really is a stomach bug, or vice versa — and sometimes there are specific symptoms that can offer up some clues.

“Many people use the term ‘flu’ to refer to a wide range of illnesses,” said Sayeed U. Khan, D.O., pediatrician with Norton Children’s Medical Group – Fern Creek. “With influenza, we tend to have more upper respiratory symptoms, whereas hallmark symptoms of a stomach virus mainly focus on gastrointestinal issues.”

Cough, congestion, body aches? Probably the flu.

The flu is a contagious respiratory illness caused by the influenza virus. It infects the nose, throat and lungs.

Symptoms of the flu can include:

  • Fever
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Body aches
  • Headache
  • Chills
  • Fatigue
  • Sometimes diarrhea and vomiting

People with flu spread the virus through tiny droplets when they cough, sneeze or talk. These droplets can land in the mouths or noses of people who are nearby. The flu virus also can live on surfaces such as shopping carts and doorknobs.

Germs make their way into the body and can lead to illness when someone gets the virus on their hands, then touches their eyes or mouth.

Antiviral medication can treat flu. It is most effective if taken within the first 24 to 48 hours of flu symptoms and will help lessen the severity. The flu vaccine is the best way to prevent serious illness. The vaccine is available for children ages 6 months and older.

If your child has the flu and symptoms worsen, it may warrant immediate medical attention. Some emergency 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

Diarrhea, intense nausea, vomiting? Could be a stomach virus.

Medically speaking, a stomach virus often is associated with norovirus or rotavirus and is not the same as the flu virus.


Symptoms of a stomach virus can include:

  • Diarrhea
  • Throwing up
  • Nausea
  • Stomach pain
  • Sometimes fever, headache and body aches

Symptoms usually develop 12 to 48 hours after exposure, and most people will experience the symptoms for one to four days.

Unfortunately, the only treatment for a norovirus stomach bug is supportive care that includes drinking plenty of fluids, eating a bland diet and resting. The virus has to run its course. If the virus lingers past four days or your child’s symptoms worsen, seek medical attention.

No matter what, drink plenty of fluids!

A common concern with both illnesses can be dehydration, so it’s important to drink lots of fluids.

“Fluid intake and rest are important with any virus,” Dr. Khan said. “We recommend that you avoid caffeinated drinks, drinks high in sugar and dairy products if you are experiencing vomiting and diarrhea.”

Norton Now: Care when you need it

If your child has symptoms of either virus, Norton eCare providers are available 24/7 to evaluate the child and provide a treatment plan through an online video visit. Video visits are available for children ages 2 and older. Schedule a visit here.

Norton Immediate Care Centers and Norton Prompt Care at Walgreens Clinics also are available with convenient hours throughout the region.