Gastroenteritis

Also known as: Upset stomach, tummy ache

Closeup of hands being washed with soap and water.Gastroenteritis is commonly called the stomach flu. It is an inflammation of the gastrointestinal tract, which includes your stomach and intestines. Most cases of gastroenteritis are caused by viruses. Bacterial gastroenteritis (caused by bacteria) usually causes severe symptoms. It can even be fatal. This sheet tells you more about bacterial gastroenteritis, how it can be prevented, and how to care for it.

How does bacterial gastroenteritis spread?

  • Contaminated food or water. You’re most likely to get gastroenteritis by consuming food or water containing harmful bacteria (such as salmonella, Campylobacter, and E Coli). Food can become contaminated when food handlers don’t wash their hands or when food isn’t stored, handled, or cooked properly.

  • Fecal-oral route. People with bacterial gastroenteritis have harmful bacteria in their stool. When they don’t wash their hands well after using the bathroom, they can spread the germs to objects. If you touch the same objects, you can pick up the germs on your hands and transfer them to your mouth.

What are the symptoms of bacterial gastroenteritis?

Many kinds of bacteria cause gastroenteritis. So, symptoms can vary. In some types of gastroenteritis, symptoms come on quickly. In others, they don’t appear for 24 to 48 hours. Symptoms can range from mild to severe and may include:

  • Watery diarrhea

  • Nausea and vomiting

  • Fever and chills

  • Belly (abdominal) pain

  • Blood in the stool (in severe cases)

How is bacterial gastroenteritis diagnosed?

Your healthcare provider will take a complete health history. Be sure to mention any recent trips and what you ate before you became ill. Keep in mind that symptoms may not appear for a day or 2 after you become infected. You may be asked to provide a sample of your stool. This is sent to a lab for testing. Don’t forget to check with your provider or hospital emergency department to learn the test results. In some cases, you will be asked to see your provider for follow-up care.

How is bacterial gastroenteritis treated?

  • Bacterial gastroenteritis often goes away without treatment. In some cases, symptoms are gone in a day or 2. In others, symptoms linger for weeks. In certain cases, it can take months for your bowels to return to normal.

  • Replacing fluids lost through diarrhea and vomiting is important for a full recovery. If you are very dehydrated, you may need fluids through an IV (intravenous) line in the hospital.

  • Medicines that slow diarrhea may be prescribed. It depends on what your provider thinks is causing your symptoms. But these medicines can make your illness last longer.

  • Your healthcare provider will prescribe antibiotics only if your symptoms are caused by certain types of bacteria.

  • You may be admitted to the hospital if your symptoms are very severe.

Easing symptoms of bacterial gastroenteritis

In most cases, bacterial gastroenteritis is treated at home. To ease symptoms and prevent complications:

  • Get plenty of rest.

  • Drink lots of liquids to replace water lost through diarrhea and vomiting. Plain water, clear soups, and electrolyte solutions are best. (You can find electrolyte solutions in most pharmacies.) Avoid fizzy (carbonated) drinks, alcohol, coffee, tea, colas, milk, and fruit juice. These can make symptoms worse. If nausea and vomiting make it hard for you to drink, try sucking on ice chips.

  • Eat according to your healthcare provider’s instructions.

  • Until the diarrhea clears up, avoid eating fruit and all dairy except yogurt. They can make diarrhea worse.

Preventing bacterial gastroenteritis at home

  • Always wash your hands well before preparing food and after handling raw meat and poultry.

  • Wash all raw fruits and vegetables—even packaged ones—with a scrub brush or vegetable wash.

  • Use one cutting board just for meat. Wash all cutting boards and utensils in hot, soapy water after use. Clean kitchen counters with bleach or disinfectant.

  • Cook meats to a safe temperature to kill bacteria that may be present in the meat. Use a food thermometer when cooking. Follow these temperature guidelines:

    • Cook ground meat (beef, veal, pork, lamb) and meat mixtures to at least 160°F (71°C).

    • Cook fresh beef, veal, lamb, and pork (steak, roasts, chops) to at least 145°F (63°C).

    • Cook poultry (including ground turkey and chicken) to an internal temperature of at least 165°F (74°C).

  • Wash your hands well after changing diapers. Dispose of diapers carefully so bacteria doesn't spread.

  • Wash your hands well before and after contact with someone who is ill. Use soap and water or an alcohol-based hand gel containing at least 60% alcohol.

  • Wear gloves when handling clothing, bed linens, or towels belonging to a sick person. Discard the gloves after each use. Then wash your hands well. Wash bed linens and other personal items separately in hot water with detergent and liquid bleach.

Preventing gastroenteritis in healthcare settings

Many hospitals and nursing homes take these steps to help prevent the spread of gastroenteritis:

  • Handwashing. Healthcare workers wash their hands well with soap and water or use an alcohol-based hand cleaner before and after touching someone. They also wash their hands after touching any surface that may be contaminated.

  • Protective clothing. Healthcare workers wear gloves and sometimes gowns when working with people who have gastroenteritis. They remove these items before leaving the room.

  • Private rooms. People with bacterial gastroenteritis are placed in private rooms or share a room with others who have the same infection.

  • Safe food handling. Kitchen workers wash their hands often, cook foods properly, and disinfect all work surfaces.

Tips for good handwashing

Wash your hands often, and always after using the bathroom, playing with pets, and before eating or preparing food. Clean the whole hand, under your nails, between your fingers, and up the wrists:

  • Wash for at least 15 seconds. Don’t just wipe. Scrub well.

  • Rinse, letting the water run down your fingers, not up your wrists.

  • Dry your hands well. Use a paper towel to turn off the faucet and open the door.

Using alcohol-based hand gels

When your hands aren’t visibly dirty, an alcohol-based hand gel containing at least 60% alcohol is a good choice.

  • Squeeze about a tablespoon of gel into the palm of one hand.

  • Rub your hands together briskly, cleaning the backs of your hands, the palms, between your fingers, and up the wrists.

  • Rub until the gel is gone and your hands are completely dry.

When to seek medical care

  • Your symptoms get worse

  • Blood in your stool or your stools look black

  • You have signs of dehydration, such as a dry mouth, intense thirst, and little or no urine