Gastroenteritis
Although it's commonly called stomach flu, gastroenteritis isn't the same as influenza. Real flu (influenza) affects your respiratory system - your nose, throat and lungs.
Gastroenteritis attacks your stomach and bowels causing symptoms like:
- Watery, usually non-bloody diarrhea
- Abdominal cramps and pain
- Nausea, vomiting or both
- Occasional muscle aches or headache
- Low-grade fever
Gastroenteritis can be caused by parasites or bacteria but is most often caused by viruses (e.g., Norovirus). Symptoms usually appear within one to three days after you're infected and can range from mild to severe. Symptoms usually last just a day or two, but occasionally they may persist longer, up to a week or more.
Contact your health care provider if symptoms last longer than a few days. Stay home until 48 hours have passed since your last symptom.
Because the symptoms are similar, it's easy to confuse viral diarrhea with diarrhea caused by bacteria such as Salmonella and E. coli or parasites such as Giardia.