Food poisoning vs stomach flu

Food poisoning and stomach bugs, or viral gastroenteritis as it is known medically, are two common types of acute gastrointestinal (GI) illness that result in stomach upset, vomiting and diarrhea.

Millions of people catch stomach viruses and have food poisoning spells every year. In the U.S., more than 20 million stomach flu cases and around 48 million food poisoning cases are reported per year.

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

If you find yourself sick with vomiting and diarrhea, here are some tips for determining whether you’re experiencing food poisoning symptoms vs. stomach flu symptoms.

Key differences: food poisoning vs. 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 non-specific illness transmitted through food. 

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 cases caused by food contaminated with parasites or viruses. 

Unlike food poisoning, stomach bugs are 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 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 vs. 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.

Let’s take a look at what you can expect from each.

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.

According to the Centers for Disease Control and Prevention, 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 germ.

Stomach flu symptoms

Most bugs that cause stomach flu have an incubation period of 24 to 48 hours, meaning symptoms typically show up within 1 to 2 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 1-10 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 may be warranted.

How do you know when to go to the hospital for vomiting or other stomach illness symptoms? 

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

• Blood in stool or vomit
• Green or yellow-colored vomit
• Signs of severe dehydration such as rapid heartbeat, confusion, or loss of consciousness
• Fever above 102°F (see special considerations for children though)
• 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. Stay away from alcohol and coffee, which are dehydrating and will keep you passing very 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 potatoes, vegetables and plain yogurt (if you are not sensitive to dairy products).

When bacteria cause food poisoning, antibiotics may be prescribed. 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 

The path to feeling better is roughly the same even if the underlying causes of stomach viruses are significantly different than food poisoning.

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 10 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. This includes:

• Cook meat, poultry and seafood to safe internal temperatures according to the following guidelines:
  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
• 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 food poisoning or a stomach bug, 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 location. You can walk in without an appointment or you can check in online. We’ll have you back to feeling better in no time.

Written by Sarah Thebarge, Physician Assistant