The leftovers in the fridge smelled a little weird, but you went ahead and ate them. You were so hungry, you didn't even heat them up. A couple of hours later, though, you started to feel sick. Powerful waves of pain rumbled through your stomach. They went away, but not for long. Then you even threw up!

That sounds like a case of food poisoning. No one put poison in your food, but bacteria probably grew in the food in the fridge and those bacteria made you sick. Food poisoning can be mild and last just a short time or can be more serious. Let's find out how to avoid it.

What Is Food Poisoning?

Food poisoning comes from eating foods that contain germs like bad bacteria or toxins, which are poisonous substances. Bacteria are all around us, so mild cases of food poisoning are common. You may have had mild food poisoning — with diarrhea and an upset stomach — but your mom or dad just called it a stomach bug or stomach virus.

You might think the solution is to get rid of all the bacteria. But it isn't possible and you wouldn't want to do it, even if you could. Bacteria are all around us, including in food, and sometimes they can be good for us. It's confusing, but one thing is for sure — the bacteria in the rotten leftovers weren't the good-for-you kind. But you can learn how to avoid those bad germs in food.

Which Germs Are to Blame?

Foods from animals, raw foods, and unwashed vegetables all can contain germs that cause food poisoning. The most likely source is food from animals, like meat, poultry (such as chicken), eggs, milk, and shellfish (such as shrimp).

Some of the most common bacteria are:

• Salmonella (say: sal-meh-nel-uh)
• Listeria (say: lis-teer-ee-uh)
• Campylobacter (say: kam-pe-low-bak-ter)
• E. coli (say: ee kole-eye)

To avoid food poisoning, people need to prepare, cook, and store foods properly.

Do I Have Food Poisoning?

Someone who has food poisoning might:

• have an upset stomach (called nausea, say: naw-zee-uh)
• have stomach cramps
• have diarrhea (say: dy-uh-ree-uh), which may contain blood
• have a fever

Sometimes feeling sick from food poisoning shows up within hours of eating the bad food. At other times, someone may not feel sick until several days later. With mild cases of food poisoning, you will not feel sick for very long and will soon be feeling fine again.

It can be hard to tell if you have food poisoning or something else. You might do a little detective work and see who else gets the same sickness. Did they eat the same thing you did? If only people who ate that food got sick, food poisoning could be the problem.

It's one thing to get food poisoning from something in your fridge, but imagine how many people could get sick if a restaurant served food that had these bad germs in it. When that happens, people from the health department might get involved and try to figure out what happened and make sure everyone gets the medical care they need.

What Will the Doctor Do?

If you go to the doctor, he or she will ask you a lot of questions about how you're feeling, when you first felt sick, what you ate in the past few days, and if anyone else you know is also sick. The doctor might also take a sample of your stool (poop) and urine (pee) to test for possible germs that might have caused food poisoning.

The type of treatment you'll get for food poisoning will depend on the specific germ that is making you sick. The doctor might give you medicine, but most of the time someone who has food poisoning doesn't need to take medicine.

It's also rare that a kid with food poisoning would need to go to the hospital. Usually, only people who get really dehydrated have to go to the hospital. Being dehydrated means your body has lost too much fluid due to diarrhea and vomiting. A dehydrated person can get fluids and medicine through an IV at the hospital. To keep from getting dehydrated, try to keep drinking fluids when you are sick.

You may also need to go to the hospital if you have blood in your poop. If you do see blood in your poop, you should definitely tell your parents about it.

How to Fight the Germs

Many things can be done to prevent food poisoning. These precautions should be taken at every stage a food takes — from preparation to cooking to storing leftovers. A lot of this responsibility falls on grown-ups, but kids can help fight germs, too. One of the best ways is to wash your hands if you're helping to prepare foods.

When should you wash? Before you start helping — so germs from your hands don't get on the food — and after so you don't pass along germs from the food to yourself or anyone else. If you don't, here's how germs can travel:

1. You help make hamburger patties.
2. You get bad bacteria from the raw ground beef on your hands.
3. You hold your little sister's hand.
4. She uses that hand to eat a snack.
5. Now the bacteria have made it inside and can make her sick.

Other steps you can take to keep your food safe include:

• Wash fruits and vegetables well before eating them.
• Only eat foods that are properly cooked. If you cut into chicken and it looks pink and raw inside, tell a grown-up.
• Look at what you're eating and smell it, too. If something looks or smells different from normal, check with an adult before eating or drinking it. Milk is a good example. If you've ever had a sip of sour milk, you know you never want to taste that again! Mold (which can be green, pink, white, or brown) is also often a sign that food has spoiled.
• If you're going to eat leftovers, ask a grown-up for help heating them up. By heating them, you can kill bacteria that grew while it was in the fridge.
• Check the date. Lots of packaged foods have expiration dates or "sell by" (which means that the food should leave store shelves by that time) dates. Don't eat a food if today's date is after the expiration date. Use it before it expires. Ask an adult for help deciding if it's past the sell by date.
• Cover and refrigerate food right away. Bacteria get a good chance to grow in foods that sit at room temperature. By putting food in the fridge, you're putting the chill on those bad germs!

Reviewed by: J. Fernando del Rosario, MD
Date reviewed: March 2012