Food poisoning vs. stomach flu

Written by Sarah Thebarge, Physician Assistant; Medically reviewed by Dr. Betsy Koickel, MD on September 10th, 2025.

Millions of people catch the stomach bug or have food poisoning every year. The Centers for Disease Control and Prevention (CDC) reports more than 48 million food poisoning cases per year and over 685 million cases of the stomach bug. These numbers are probably low as many cases go unreported.

No matter how many times you've had them in the past, these two stomach ailments are uncomfortable. Since the symptoms of both illnesses are similar, it can be tough to differentiate between stomach flu vs. food poisoning based on symptoms alone.

While food poisoning and stomach bug symptoms have similar symptoms, they have different underlying causes. If you find yourself sick with vomiting and diarrhea, here are some tips for determining whether you’re experiencing food poisoning vs. stomach flu symptoms.

Difference between food poisoning and stomach flu

There is no science-backed definition for food poisoning – it’s a more generalized term. When people talk about food poisoning, they’re referring to a nonspecific illness transmitted through food.

Thirty-one known pathogens can cause foodborne illness and many more are unknown. Here are a few common types of bacteria that can be present in undercooked or spoiled food and lead to food poisoning:

Campylobacter
Clostridium perfringens
E. coli
Listeria
Salmonella
Staphylococcus aureus

Although bacteria are usually the culprit behind food poisoning, there are also cases caused by food contaminated with parasites or viruses.

Viral gastroenteritis is slightly different from food poisoning, as the stomach bug is not contracted via contaminated foods. You catch a stomach virus like you catch the flu – by coming into contact with someone who is infected. Examples of stomach bugs include some strains of adenovirus, coronavirus, norovirus, or rhinovirus.

Put simply, a viral infection is what causes the stomach flu, and eating something that is spoiled or contaminated with harmful bacteria, viruses or parasites is what causes food poisoning.

It’s hard to differentiate between stomach flu and food poisoning based on symptoms alone since both illnesses wreak havoc on your digestive system. However, it’s important to identify the root cause of your symptoms for proper treatment. A healthcare provider can help determine your illness and recommend the appropriate treatment.

Food poisoning symptoms

The onset of most food poisoning usually occurs within a few hours of eating contaminated food, but some types of food poisoning can take 24 hours or longer to make you sick. This is what makes it hard to figure out exactly which food made you ill.

According to the CDC, food poisoning infections can range from mild to severe, requiring hospitalization depending on the type of germ you ingest.

General food poisoning symptoms include:

Chills
Diarrhea
Fever
Nausea
Stomach pain or cramping
Vomiting

Food poisoning symptoms usually subside pretty quickly, often within several hours, as your body works to rid itself of the food that made you sick and the pathogen it contained.

Stomach flu symptoms

Most viruses or bacteria that cause stomach flu have an incubation period of 24 to 48 hours, meaning symptoms typically show up within one to two days after coming into contact with a virus.

General stomach flu symptoms include:

Body aches
Chills
Diarrhea
Fever
Headache
Nausea
Stomach pain or cramping
Vomiting

Stomach bugs typically take longer than food poisoning to resolve. You may be sick with the stomach flu anywhere from one to ten days, depending on your immune system and the individual strain of the virus.

When to go to the ER?

Most of the time, it's fine to visit an urgent care center if you need help deciphering whether you’ve come down with food poisoning vs. the stomach flu. However, there are a few instances where a trip to the emergency room could be warranted if the symptoms are severe or you have other medical conditions that can result in severe complications.

If you're experiencing any of the symptoms below, seek emergency medical attention immediately:

Blood in stool or vomit
Fever above 102 F (see special considerations for children)
Green or yellow-colored vomit
Signs of severe dehydration such as rapid heartbeat, confusion, or loss of consciousness
Severe and/or constant pain in the abdomen
Trouble swallowing or breathing

Treatment for food poisoning

Since food poisoning results in your body expelling fluids, staying hydrated is key. You’ll want to replenish lost fluids with water, electrolyte drinks, or tea. Drink these fluids in small sips to prevent them from inducing vomiting. The goal is to keep them down as much as possible.

Avoid alcohol and coffee, as they can dehydrate your body and lead to frequent, watery diarrhea.

Avoid solid food and focus on fluids if you’re vomiting. When you feel that you can handle solid food, slowly introduce bland and easy-to-digest foods. The BRAT diet is a good starting point.

BRAT stands for:

B - Bananas

R - Rice

A - Apples

T - Toast

BRAT foods are plain, starchy, and low in fiber, which also happens to be a tried-and-true toddler diarrhea remedy. Other easy-to-digest foods include skinless potatoes, cooked vegetables, and plain yogurt (if you are not sensitive to dairy products). Avoid raw fruits and vegetables and spicy or highly seasoned foods until you feel better. Stay away from alcohol and caffeine.

The need for an antibiotic depends on the type of bacteria causing the food poisoning. Unlike viruses, bacteria can be fought with prescription medication, so be sure to seek medical attention if symptoms do not quickly resolve. If antibiotics are not needed, staying hydrated and getting plenty of rest is usually your best bet to feeling better.

Treatment for stomach flu

Since the symptoms are so similar, the path to feeling better with the stomach flu is roughly the same, even if the underlying causes of stomach viruses differ.

Rest, hydration, and electrolyte replenishment are the main treatment goals when you have vomiting and diarrhea. Try taking small sips of water or an electrolyte drink every ten to 15 minutes if you’re having difficulty keeping anything down.

Be careful not to gulp fluids, as this can overwhelm your sensitive stomach and trigger more nausea and vomiting.

As with food poisoning treatment, bland foods or the BRAT diet will be easiest on your stomach as you recover from the stomach flu. Avoid overly seasoned and spicy food, which can irritate a sensitive stomach.

Most stomach viruses can’t be treated with prescription medication, but over-the-counter medications for stomach pain, fever, and diarrhea can make you more comfortable.

How to prevent getting sick

By following a few simple tips, you can take the proper precautions to reduce the chances of food poisoning and stomach viruses. Even if you currently have one of these illnesses, it pays to take preventative measures in the future!

Prevent food poisoning

The best way to prevent food poisoning is to practice safe food handling and cooking when preparing meals and snacks. This includes:

Cook meat, poultry, and seafood to safe internal temperatures according to the following guidelines. Always use a meat thermometer to ensure the proper temperature.
Beef: 160 F
Pork: 145 F
Poultry: 165 F
Keep cooking surfaces clean, including countertops and cutting boards.
Leftovers should be refrigerated or frozen within two hours of cooking. There is no need to leave anything out on the counter to “cool” before storing it.
Maintain appropriate cold storage temperatures:
The refrigerator should be 40 F or below
The freezer should be 0 F
Separate raw meat, poultry, seafood, and uncooked eggs from produce and prepared foods (i.e., avoid cross-contamination).
Wash your hands before cooking and each time you handle raw ingredients.

You can also reduce your risk of food poisoning by not drinking or cooking food in water that is non-potable.

If food appears or smells questionable or you don’t know how long it’s been sitting out at room temperature, don’t consume it.

Prevent stomach flu

Since viruses that cause stomach flu are passed from person to person, good handwashing is your best bet at preventing a stomach bug.

Make sure to wash your hands and refrain from touching your eyes, ears, nose, and mouth after coming into contact with an infected person. If you hear a stomach bug going around your workplace, school, or community, wash your hands more frequently and keep hand sanitizer with you for cleaning on the go.

Be mindful of those who have a stomach bug, and keep your distance when possible. You should also avoid sharing food and drinks with someone who has a stomach bug.

Visit urgent care for stomach flu

Whether it’s the stomach flu or food poisoning, it’s never a fun time for the infected person. The good news is these two illnesses tend to pass quickly.

The next time you’re hit with a stomach illness, remember to stay hydrated, eat easily digested-food, and rest. If your symptoms don’t resolve after a couple of days or you’re experiencing signs of dehydration, seek medical care.

For mild and moderate cases of stomach flu, urgent care centers can assess your symptoms, help you pinpoint the cause, and recommend a treatment plan.

If you need help assessing and treating stomach flu, head to one of your nearest urgent care locations. You can walk in or save your spot online.

References:

Difference between food poisoning and stomach flu

Food poisoning symptoms

Stomach flu symptoms

When to go to the ER?