Gastroenteritis, also known as stomach flu, typically causes the following signs and symptoms:
- Nausea and vomiting: These are common symptoms of gastroenteritis, and can be caused by the inflammation of the stomach and intestines.
- Diarrhea: Gastroenteritis can cause loose, watery stools, often accompanied by abdominal cramps and bloating.
- Abdominal pain and discomfort: In addition to cramps and bloating, gastroenteritis can cause general abdominal pain and discomfort.
- Fever: Some people with gastroenteritis may develop a low-grade fever, usually less than 101°F (38.3°C).
- Headache: Some people with gastroenteritis may experience headaches, which are often caused by dehydration.
- Dehydration: Gastroenteritis can cause dehydration, especially if vomiting and diarrhea are severe. Signs of dehydration may include dry mouth, thirst, decreased urine output, and dizziness.
When to see a doctor
If you’re an adult, call your health care provider if:
- You’re not able to keep liquids down for 24 hours
- You’ve been vomiting or having diarrhea for more than two days
- You’re vomiting blood
- You’re dehydrated — signs of dehydration include excessive thirst, dry mouth, deep yellow urine or little or no urine, and severe weakness, dizziness or lightheadedness
- You notice blood in your bowel movements
- You have severe stomach pain
- You have a fever above 104 F (40 C)
For infants and children
See your child’s health care provider right away if your child:
- Has a fever of 102 F (38.9 C) or higher
- Seems tired or very irritable
- Is in a lot of discomfort or pain
- Has bloody diarrhea
- Seems dehydrated — watch for signs of dehydration in sick infants and children by comparing how much they drink and urinate with how much is normal for them, and watching for signs such as a dry mouth, thirst and crying without tears
If you have an infant, remember that while spitting up may be an everyday occurrence for your baby, vomiting is not. Babies vomit for a variety of reasons, many of which may require medical attention. Call your baby’s doctor right away if your baby:
- Has vomiting that is frequent
- Hasn’t had a wet diaper in six hours
- Has bloody stools or severe diarrhea
- Has a sunken soft spot (fontanel) on the top of his or her head
- Has a dry mouth or cries without tears
- Is unusually sleepy, drowsy or unresponsive
Note that the symptoms of gastroenteritis typically develop within one to three days after exposure to the virus, bacteria, or parasite that caused the infection. The illness usually resolves on its own within a few days to a week, but in some cases, medical treatment may be necessary to manage symptoms and prevent complications.