When should you see a doctor for stomach flu (gastroenteritis)?

You’ll likely be able to fight off stomach flu virus without seeing a healthcare provider. If you have signs of dehydration (dark, infrequent/low urine output, dry mucous membranes, lightheadedness, dizziness, etc.), you should seek medical care right away. Also call your healthcare provider if you have:

  • High fever.
  • Bloody diarrhea.
  • Severe pain.
  • Symptoms that fail to improve/resolve over time.

How is stomach flu diagnosed?

Healthcare providers often can diagnose stomach flu from your symptoms. But your provider may want to rule out other illnesses with some tests:

  • Stool samples: Tests look for bacteria, viruses or parasites in your stool
  • Sigmoidoscopy: A doctor inserts a thin, flexible tube with a tiny camera from the anus into the lower large intestine to look for signs of inflammatory bowel disease. The sigmoidoscopy is a 15-minute procedure that doesn’t usually require sedation.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy