Many people talk about the "stomach flu" when they're feeling sick to their stomachs. It isn't the same as influenza, or the flu. Stomach flu is an illness called gastroenteritis (say: gas-tro-en-tuh-rye-tus), which is usually caused by a virus.
Someone with gastroenteritis may have stomach cramps, diarrhea (say: dye-uh-ree-uh), a fever, and nausea (say: naw-zee-uh), and might throw up. He or she will probably feel pretty sick for a day or two but will then get better.
There is no vaccine or cure for gastroenteritis. If you have it, you'll want to rest until you feel better. If you're throwing up, don't eat solid food. Instead, sip fluids, such as water, or try a popsicle. Your mom or dad also might give you an oral rehydration (say: ree-hye-dray-shun) solution. That's a fancy name for those special fruit-flavored drinks that contain carbohydrates and electrolytes — stuff your body can get low on when you're dehydrated from diarrhea or throwing up.
Once you stop throwing up, you can try other kinds of clear liquids like chicken broth and juices. When you start to feel better, try eating bland foods like gelatin, toast, pretzels or crackers, bananas, rice, and plain noodles. As your digestive system returns to normal, you can gradually go back to eating what you usually do.
Gastroenteritis is contagious (say: kun-tay-jus), which means that someone who has it can spread it to other people. It's spread by close contact with the person who is sick or by eating food that's contaminated. That's why it's important to wash your hands, especially before you eat and after going pee or poop!