Topic Overview

What is gastroenteritis?

Gastroenteritis is an upset stomach. It causes nausea and vomiting. You may also have diarrhea or a fever. It is sometimes called "stomach flu," but it is not the flu. Germs like viruses and bacteria can cause it.

You can catch it from someone else who has it, or you can get it from food poisoning. Food poisoning can happen if you eat foods that contain harmful germs. Germs can get into food while the food is growing, during processing, or when it is prepared. You may have become ill after eating meat or eggs that weren't cooked enough or by eating other unsafe foods or drinking unsafe water.

You will probably begin to feel better in 1 or 2 days, but you might feel bad for a week. In the meantime, get plenty of rest, and make sure you do not become dehydrated. Dehydration occurs when your body loses too much fluid. This can happen when you throw up a lot or have diarrhea.

What should you do at home?

• Drink plenty of fluids. Choose water and other caffeine-free clear liquids until you feel better. If you have kidney, heart, or liver disease and have to limit fluids, talk with your doctor before you increase how much fluid you drink.
• Drink fluids slowly, in frequent, small amounts. Drinking too much too fast can cause vomiting.
• Electrolytes should also be replaced, especially if vomiting or diarrhea last longer than 24 hours. Electrolytes are minerals in your blood that keep many systems in your body working smoothly. If you have a long period of vomiting and diarrhea, you can lose minerals. Sports drinks, which contain a mix of salt, sugar, and minerals, may help replace electrolytes.
• When you feel like eating, start with mild foods, such as dry toast, yogurt, applesauce, bananas, and rice. Avoid spicy, hot, or high-fat foods, and do not drink alcohol or caffeine for a day or two. Do not drink milk or eat ice cream or other dairy foods until you are feeling better.

When should you call a doctor?

You can usually take care of gastroenteritis at home.

• But call 911 or other emergency services immediately if:
  • You have signs of severe dehydration. These include little or no urine; sunken eyes, no tears, and a dry mouth and tongue; fast breathing and heartbeat; feeling very dizzy or lightheaded; and not feeling or acting alert.
  • You think you may have food poisoning from a canned food and you have symptoms of botulism (blurred or double vision, trouble swallowing or breathing, muscle weakness).
• Call your doctor immediately if:
  • Severe diarrhea (large amounts of loose stool every 1 to 2 hours) lasts longer than 2 days in an adult.
  • Vomiting lasts longer than 1 day in an adult.
  • You are pregnant and believe that you have been exposed to listeriosis or toxoplasmosis. For more information on toxoplasmosis, see the topic Toxoplasmosis During Pregnancy.
  • You have sudden, severe belly pain.
  • Your stools are black and tarry or they have streaks of blood.
• Talk to your doctor if:
  • You have symptoms of mild dehydration (dry mouth, dark urine, not much urine) that get worse even with home treatment.
  • You have a fever that lasts more than 1 or 2 days.
  • You are not feeling better after 1 week of home treatment.