The stomach flu refers to viral gastroenteritis, an inflammation of the digestive tract caused by viruses like norovirus or rotavirus. It's not actually related to the flu (influenza), despite the name.
Viral gastroenteritis attacks the lining of your stomach and intestines, causing inflammation. This disrupts digestion and leads to symptoms like nausea, vomiting, diarrhea, and abdominal cramps. The illness typically lasts 1-3 days, though some cases persist longer.
The most common causes are:
According to the Centers for Disease Control and Prevention (CDC), norovirus alone causes 19-21 million illnesses annually in the U.S.
Many people mistake food poisoning for stomach flu. Food poisoning is usually caused by bacteria (like Salmonella or E. coli) or toxins in food, while stomach flu is viral. Symptoms overlap, but food poisoning often includes fever and blood in stools.
For a detailed comparison of flu symptoms vs. stomach flu symptoms, see this guide.
Sarah woke up with sudden nausea, vomiting, and diarrhea. She assumed it was food poisoning from last night's dinner but had no fever. Since her symptoms matched viral gastroenteritis, she rested, hydrated with electrolyte solutions, and recovered within 48 hours. Had she experienced fever or blood in stool, bacterial infection would have been more likely.
Stomach flu spreads easily. To prevent it, wash hands frequently, avoid contaminated food, and disinfect surfaces. Treatment focuses on hydration-oral rehydration solutions (ORS) help replace lost fluids. Over-the-counter medications may ease symptoms, but antibiotics won't help since it's viral.
Seek care if symptoms persist beyond 3 days, dehydration occurs, or blood appears in vomit or stool. Severe cases may require hospitalization for IV fluids.