Stomach Flu vs. Food Poisoning

General Health and Preventive Care  /  Blog

Stomach Flu vs. Food Poisoning

Sean Lee

Written by Sean Lee

Sean Lee

Sean Lee

Sean is an Orange County native living in Los Angeles. With experience in healthcare, finance, and public policy, he’s passionate about helping startups improve the U.S. healthcare system.

March 16, 2021 / Read Time 7 minutes

Stomach Flu or Food Poisoning: What’s the Difference?

Abdominal pains, fever, and gas are common signs of many conditions, including both the stomach flu and food poisoning. The two are commonly confused. The stomach flu and food poisoning are two different conditions. 

A virus causes the stomach flu, but food poisoning is caused by bacteria, viruses, or other parasites. The former can last for days, but food poisoning usually only takes one day. Both are extremely common. The US Department of Health & Human Services estimates that there are about 48 million cases of foodborne illnesses annually, which equates to 1 in 6 Americans having a food-related illness.

Speak with a Doctor Online

Although they share similar symptoms, there are differences to be aware of between the two. The signs and symptoms of the stomach flu can vary greatly from person to person and naturally develop within a day or as fast as two to three hours. Understanding the differences between stomach flu vs. food poisoning can ensure you take the right steps towards recovery as well as speed up doctor visits.

  1. 1

    Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

  2. 2

    See a doctor, get treatment and a prescription at your local pharmacy.

  3. 3

    Use your health insurance just like you normally would to see your doctor.

What Is the Stomach Flu?

The phrase “stomach flu” does not necessarily make it the flu. It is not caused by the influenza virus, like most upper respiratory problems such as in your nose, throat, and lungs, and should not be confused with the “seasonal flu.” 

The medical term for the common stomach flu is “viral gastroenteritis.”

Stomach Flu Symptoms

Viral gastroenteritis is an intestinal infection associated with these symptoms:

  • Nausea or vomiting: Your body recognizes the illness as a poison, so it reacts to the discomfort by vomiting.

  • Watery diarrhea: Severe dehydration can also yield dark or decreased urine. Keep track of how long you have been having diarrhea if it has been more than three days, and see a doctor immediately if you have blood in your stool.

  • Low-grade fever: A fever is the immune system’s attempt to combat illness such as viruses and bacteria infection. By heating up the body, fevers create an environment that tackles temperature-sensitive agents.

  • Abdominal pain and cramping: A stomach bug can produce moderate pain.

How Long Does the Stomach Flu Last? 

The stomach flu usually starts one to three days after exposure and can take up to 10 days to fully heal. 

You may also be wondering how long the stomach flu is contagious? The stomach flu is highly contagious, and the length of that will depend on the type of virus that caused the infection. You are still contagious for up to three days after recovery in some cases. 

What Is Food Poisoning?

Food poisoning is an extensive term for some type of bacteria that has affected you. 

Food Poisoning Symptoms

Your immune system induces food poisoning to expel the illness and can present the following symptoms:

  • Bloating and gas: Passing gas clears gas from the digestive tract, but lingering gas stuck in the tract can cause pain.

  • Fever: You should see a doctor immediately when above 101.5 F to avoid severe dehydration.

  • Muscle aches: Certain bacteria such as Staphloccus aureus and Campylobacter jejuni cause muscle pains. Inflammatory responses or irregular blood supply cause these pains.

  • Weakness: Your body devotes a lot of energy to fight off the illness, and the loss of calories and electrolytes can make you feel weak.

  • Abdominal pain and cramping: Your illness’s primary source is in your stomach region, so this area could experience mild to moderate discomfort. Although a stomach bug is a more general discomfort, food poisoning will yield a sharp stabbing pain.

How Long Does Food Poisoning Last? 

Food poisoning has a rapid onset of symptoms, usually appearing two to six hours after eating contaminated food or drinks. It may last up to 48 hours, but can sometimes resolve itself within 24 hours. 

How Do I Know If It's a Stomach Virus or Food Poisoning?

Although the symptoms of stomach flu and food poisoning can overlap, the primary indicator of which you have will be the timing of symptoms. 

Viral stomach flu will incubate for roughly 24-48 hours after exposure to the virus, whereas food poisoning will be much faster at 2-6 hours after eating contaminated food. Many cases of the stomach flu resolve in a few days, with more prolonged cases lasting up to 10 days. Most food poisoning cases last only for a day or two.

Stomach Flu

Food Poisoning 

Caused by viruses 

Caused by either virus, bacteria, or parasite

Lasts up to 10 days 

Lasts up to two days 

Very contagious, can spread quickly

Cannot pass person to person, only by cross-contamination of germs from food or drinks

Less common

Very common

Symptoms: fever, headache, muscle aches, belly pain, stomach cramps, loss of appetite, vomiting, diarrhea

Symptoms: nausea, vomiting, stomach pain or cramping, diarrhea, fever, dizziness 

How to Prevent Food Poisoning and the Stomach Flu

Both food poisoning and stomach flu are best cured by preventative methods instead of recovery after the fact.

Preventing food poisoning can be difficult, but there are a few steps that can help. Since you are just as likely to get it from your kitchen as you are at an outside restaurant, you can take the following steps to avoid serious illnesses:

  • Wash your hands, so you do not bring unnecessary agents into your kitchen and do not mix foods

  • Keep your kitchen clean in case your utensils have come into contact with other foods conducive to viral growth

  • Be careful of raw meat and cook it properly, so you do not get sick

  • Do not consume expired food even if the food looks and smells fine, as you should respect the “use by” date to be careful of all of the harmful microscopic organisms.

  • Be mindful of your leftovers in case they have been left outside of proper refrigeration for too long or have already expired

If you are dining with street food such as at food trucks, you should be mindful of exploring street food without the perils as sanitary food preparation is key to avoid food poisoning.

Since the stomach flu is contagious, you can prevent exposure to it with the following:

  • Practice proper hand hygiene

  • Keep your kitchen clean

  • Do not prepare foods while infected

  • Avoid contact with the infected

Make sure to practice these precautions even if you feel fine as you are contagious for approximately three days after recovery.

Even with safe practices and regulations in place, such as mandated hand washing and kitchen inspections, it is essential for you to recognize stomach pains and how to best take the appropriate steps for your recovery.

What to Do If You Have the Stomach Flu or Food Poisoning?

Although most cases can be treated at home with lots of fluid with electrolytes and rest, severe symptoms such as diarrhea spanning several days and high fevers should not be overlooked.

Your body is actively fighting off the causes of your pain, so take it easy while you recover. While in recovery, you should take the necessary precautions to avoid spreading the infection:

  • Wash your hands in warm, soapy water for at least 20 to 30 seconds

  • Avoid sharing your food or drink to prevent spreading the illness to others

  • Take time off from school or work to allow the illness to heal

Stomach Flu and Food Poisoning Treatment

While your body is in recovery, you should be taking it easy. If you are keeping food down, you should follow a simple diet of bananas, rice, apple sauce, and toast (sometimes called BRAT) in addition to liquids that are heavy in electrolytes such as a sports drink. It is vital for your health to maintain a good diet while in recovery mode to replace some of the calories and electrolytes you’re losing. 

Like most recoveries, you should avoid alcohol, caffeine, and dairy if you are sensitive to these groups. Similarly, like most illnesses, the pregnant, young, and elderly are more prone and should be extra careful when monitoring recovery.

Food Poisoning Remedies

Since the stomach flu is viral, it cannot be treated with antibiotics. Instead, it is possible to use over-the-counter (OTC) medicines to alleviate the symptoms of the stomach flu and food poisoning, such as ibuprofen and Tylenol for fevers as well as aches. These kinds of medications can be taxing on kidneys due to dehydration and should be monitored carefully with food as well as proper fluid intake to keep your body hydrated.

  1. 1

    Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

  2. 2

    See a doctor, get treatment and a prescription at your local pharmacy.

  3. 3

    Use your health insurance just like you normally would to see your doctor.

When to Contact a Doctor

Regarding your diagnosis of the stomach flu vs. food poisoning, a doctor will ask you about your symptoms and medical history. Your doctor may also take a stool sample to check for key signs such as blood or a noticeable bacteria count.

If you exhibit any symptoms of the stomach flu or food poisoning for more than a prolonged period of time, then you should make an appointment with your doctor, who can tell you about the difference between food poisoning and stomach flu.

If you are an adult, then you should contact your doctor when you are:

  • Not able to keep liquids down for more than 24 hours

  • Vomiting for more than two days

  • Vomiting blood

  • Experiencing excess dehydration such as darker urine and a dry mouth

  • Noticing blood in your stool

  • Experiencing a fever above 102 °F for at least a few days

If you are a parent and feel that your child is exhibiting symptoms, you should immediately consult with your doctor. Although most cases of either illness are not fatal, extra caution should be used when examining those who are young, elderly, or pregnant.

If you experience any of the symptoms above, book a virtual appointment with a top U.S. doctor at PlushCare today.

Read More About Stomach Flu vs. Food Poisoning


PlushCare is dedicated to providing you with accurate and trustworthy health information.

Most PlushCare articles are reviewed by M.D.s, Ph.Ds, N.P.s, nutritionists and other healthcare professionals. Click here to learn more and meet some of the professionals behind our blog. The PlushCare blog, or any linked materials are not intended and should not be construed as medical advice, nor is the information a substitute for professional medical expertise or treatment. For more information click here.

Our commitment to you.

PlushCare is dedicated to providing you with accurate and trustworthy health information.

Research from sources you can trust

Medical reviews by field experts

Frequent content updates