Stomach bug or food poisoning – how to tell the difference

July 13, 2015 Providence Health Team

Symptoms of a stomach virus and food poisoning are similar. Learn the difference between these conditions and when to see a doctor.

You’re feeling weak, vomiting and have a bad case of diarrhea. Is it that nasty stomach bug that’s going around? Or did the take-out from that hole-in-the-wall give you food poisoning? What’s the difference, anyway?

Norovirus and rotovirus - the most common causes of stomach bugs - are very contagious. You’re most likely to get hit with them during peak flu season, which runs November to April. Food poisoning, on the other hand, isn’t generally contagious and it can strike any time you consume contaminated food or water.


Symptoms of a stomach virus and food poisoning can be hard to tell apart. Common symptoms for both include:

  • Stomach cramps
  • Vomiting
  • Watery diarrhea, for up to five days for an adult and two days for a child
  • Fever
  • Dehydration, including dark or low-volume urine, or dry skin or mouth
  • Muscle aches or weakness
  • Headache, light-headedness or dizziness

It might be food poisoning if …

In cases of food poisoning, symptoms may appear quickly, often within a few hours of eating. And they can be alarming:

  • Extreme abdominal pain or cramping
  • Vomiting more than four times in a day
  • Inability to keep even liquids down
  • Severe diarrhea for more than three days
  • Blood or pus in vomit or stool
  • Fever of 101.5 or more in adults and 100.4 in children
  • Blurred vision
  • Difficulty breathing or speaking

When to seek medical attention

When you have a stomach bug or food poisoning, deciding whether to see your primary care provider immediately or wait it out can be tough. A decision often depends on how sudden and severe your symptoms are. If you’re pregnant, see a provider right away. And because young children and the elderly are more susceptible to becoming seriously sick, they should err on the side of caution as well.

Be prepared to answer questions about your symptoms and try to remember what you last ate: any dairy or egg-based foods that could have spoiled, raw or undercooked seafood or meat, vegetables from a salad bar that may have been contaminated.

Your care provider might test your blood and stool to determine whether you have a viral or bacterial infection.


Stomach bug: Unfortunately, it can’t be cured with medicine – viruses aren’t responsive to antibiotics. All you can really do is treat your symptoms so you feel better. Take pain relievers, fever reducers and anti-diarrhea and anti-nausea medicines as needed, or as prescribed by your doctor. Rest and drink clear liquids to prevent dehydration.

Food poisoning: Most cases of food poisoning are mild and don’t require medical treatment. Symptoms are best treated with rest, drinking liquids and stomach-calming medicines. Hospitalization can be required for severe cases of food poisoning to remove toxins from the body and replenish lost fluids intravenously.

If you come down with something but aren’t sure if it’s a stomach bug or food poisoning, remember you can always contact your Providence primary care provider.

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