Stomach flu (viral gastroenteritis) doesn’t have a cure, so treatment comes down to managing symptoms and staying hydrated while the virus runs its course. Most people feel better within one to three days. The priorities are simple: replace lost fluids, eat what you can tolerate, rest, and know which warning signs mean you need medical help.
Hydration Is the Top Priority
Vomiting and diarrhea drain your body of water and electrolytes fast. Dehydration is the main risk of stomach flu, not the virus itself. Your goal is to replace fluids steadily, even when drinking feels like the last thing you want to do.
Take small, frequent sips rather than gulping a full glass. If you’re vomiting, wait 15 to 30 minutes after an episode before trying again. Good options include water, oral rehydration solutions (like Pedialyte or store-brand equivalents), clear broths, and diluted juice. Oral rehydration solutions are especially useful because they contain a balanced mix of sugar and electrolytes that your intestines can absorb efficiently. Sports drinks work in a pinch but contain more sugar than ideal.
Avoid alcohol, caffeinated drinks, and anything very sugary, as these can pull more water into your intestines and worsen diarrhea. If you can’t keep any fluids down at all, that’s a sign you may need medical attention for IV fluids.
What to Eat (and When)
You don’t need to force food while you’re actively vomiting. Once you can keep liquids down and feel a flicker of appetite, start with bland, easy-to-digest foods: saltine crackers, plain rice, toast, oatmeal, brothy soups, boiled potatoes, or dry cereal.
You may have heard of the BRAT diet (bananas, rice, applesauce, toast). It’s fine for the first day when you’re at your worst, but sticking to it longer than that actually slows recovery. It lacks protein, calcium, vitamin B12, and fiber, all of which your body needs to heal. The American Academy of Pediatrics no longer recommends it for children because it’s too restrictive and can delay gut recovery.
As your stomach settles, add foods with more nutritional value: scrambled eggs, skinless chicken or turkey, and cooked vegetables. Avoid greasy, spicy, or heavily seasoned food until you feel fully normal. Dairy can be tricky for some people during recovery because the virus temporarily reduces your ability to digest lactose, so reintroduce it gradually.
Over-the-Counter Medications
Adults can use anti-diarrheal medications like loperamide (Imodium) or bismuth subsalicylate (Pepto-Bismol) to reduce the frequency of loose stools. These won’t shorten the illness, but they can make it more manageable, especially if you need to function.
There are important exceptions. Do not use these medications if you have a fever or bloody diarrhea, as those symptoms suggest a bacterial or parasitic infection rather than a virus, and slowing your gut down in that situation can make things worse. These medications are also not safe for infants and children without a doctor’s guidance.
For nausea, ginger tea or ginger chews can help take the edge off. Acetaminophen (Tylenol) is a reasonable choice if you have body aches or a low-grade fever. Avoid ibuprofen and aspirin, which can irritate an already inflamed stomach lining.
Probiotics Probably Won’t Help
Probiotics are widely marketed for gut health, but large clinical trials have found they don’t shorten stomach flu symptoms. Researchers at Washington University tested Lactobacillus rhamnosus GG (sold as Culturelle), one of the most studied probiotic strains, in children with gastroenteritis. A parallel Canadian study tested a different probiotic. In both trials, diarrhea lasted about two days regardless of whether kids took the probiotic or a placebo. Taking them won’t hurt, but don’t count on them to speed your recovery.
How Long It Lasts
Most stomach flu caused by norovirus, the most common culprit, resolves within one to three days. You’ll typically feel the worst in the first 12 to 24 hours, with symptoms gradually tapering after that. One thing many people don’t realize: you can still spread the virus for two weeks or more after you feel better. That matters for handwashing habits and food preparation, especially if you live with young children, older adults, or anyone with a weakened immune system.
Preventing Spread at Home
Norovirus is notoriously tough to kill. Regular soap and water on your hands is more effective than alcohol-based hand sanitizer, which doesn’t reliably destroy the virus. Wash your hands thoroughly for at least 20 seconds, especially after using the bathroom and before touching food.
For contaminated surfaces (bathrooms, doorknobs, countertops), standard household cleaners aren’t strong enough. The CDC recommends a chlorine bleach solution of 5 to 25 tablespoons of household bleach (5% to 8% concentration) per gallon of water. You can also use an EPA-registered disinfectant specifically labeled as effective against norovirus. Wash any contaminated clothing or bedding on the hottest setting and dry thoroughly.
If possible, the sick person should use a separate bathroom and avoid preparing food for others until at least two days after symptoms stop.
Warning Signs That Need Medical Attention
Most stomach flu passes without complications, but dehydration can become dangerous quickly, especially in young children and older adults. Watch for these signs of dehydration: dark-colored urine, urinating much less than usual, extreme thirst and dry mouth, dizziness or lightheadedness, sunken eyes, and skin that stays “tented” when you pinch it rather than flattening back immediately.
In infants, look for no wet diapers for three hours or more, no tears when crying, a dry mouth, and unusual fussiness or sleepiness.
Seek medical care if you experience diarrhea lasting more than two days (more than one day for children), a high fever, vomiting so frequent you can’t keep fluids down, six or more loose stools per day, severe abdominal pain, or stools that are black, tarry, or contain blood. Older adults, pregnant women, and people with weakened immune systems or chronic health conditions should seek care at the first signs of gastroenteritis rather than waiting it out.