When you have diarrhea and vomiting, you may say you have the “stomach flu." These symptoms often are due to a condition called gastroenteritis.
With gastroenteritis, your stomach and intestines are irritated and inflamed. The cause is typically a viral or bacterial infection.
Symptoms of Gastroenteritis
With gastroenteritis, the main symptoms you probably have are watery diarrhea and vomiting. You might also have stomach pain, cramping, fever, nausea, and a headache.
Because of diarrhea and vomiting, you also can become dehydrated. Watch for signs of dehydration, such as dry skin and a dry mouth, feeling lightheaded, and being really thirsty. Call your doctor if you have any of these symptoms.
Stomach Flu and Children
Children can get dehydrated quickly, so if your child has the stomach flu, it’s important that you look for signs that they are very thirsty or has dry skin or a dry mouth. If you have a baby, look for fewer, drier diapers.
Keep children with gastroenteritis out of day care or school until all symptoms are gone. Check with your doctor before giving your child any medicine. Drugs used to control diarrhea and vomiting aren’t usually given to children younger than 5.
To help prevent rotavirus — the most common cause of stomach flu for children — there are two vaccines that can be given to infants. Talk to your doctor about the vaccines.
What Causes Gastroenteritis
There are many ways gastroenteritis can be spread:
- Contact with someone who has the virus
- Contaminated food or water
- Unwashed hands after going to the bathroom or changing a diaper
The most common cause of gastroenteritis is a virus. The main types are rotavirus and norovirus.
Rotavirus is the world’s most common cause of diarrhea in infants and young children. Norovirus is the most common cause of serious gastroenteritis and also foodborne disease outbreaks in the U.S.
Although not as common, bacteria such as E. coli and salmonella can also trigger the stomach flu. Salmonella and campylobacter bacteria are the most common bacterial causes of gastroenteritis in the U.S. and are usually spread by undercooked poultry, eggs, or poultry juices. Salmonella can also be spread through pet reptiles or live poultry.
Another bacteria, shigella, is often passed around in day care centers. It typically is spread from person to person, and common sources of infection are contaminated food and drinking water.
Parasites can also cause gastroenteritis, but it’s not common. You can pick up organisms such as giardia and cryptosporidium in contaminated swimming pools or by drinking contaminated water.
There are also other unusual ways to get gastroenteritis:
- Heavy metals (arsenic, cadmium, lead, or mercury) in drinking water
- Eating a lot of acidic foods, like citrus fruit and tomatoes
- Toxins that might be found in certain seafood
- Medications such as antibiotics, antacids, laxatives, and chemotherapy drugs
- CDC: “Norovirus — Overview," “Rotavirus — Prevention," “Rotavirus," “Viral Gastroenteritis."
- Cleveland Clinic: “Gastroenteritis."
- KidsHealth: “Stomach Flu."
- Medscape: “Emergent Treatment of Gastroenteritis."
- The Merck Manual Home Health Handbook: “Overview of Gastroenteritis."