Most people recover from the stomach flu (viral gastroenteritis) within one to three days, though symptoms can stretch to a full week in more severe cases. The worst of it, the intense vomiting and watery diarrhea, typically peaks in the first 24 to 48 hours and then gradually winds down.
How Long Each Phase Lasts
The stomach flu moves through a predictable arc. First comes the incubation period: for norovirus, the most common cause in adults, symptoms appear 12 to 48 hours after exposure. You might feel fine one evening and be vomiting by the next morning. Rotavirus, which is more common in young children, can cause vomiting and watery diarrhea lasting 3 to 8 days.
The acute phase is when your immune system mounts its strongest response against the virus. This is the period of active vomiting, diarrhea, cramping, and sometimes fever. For most adults, this lasts one to three days. In severe cases, or in very young children and older adults, it can persist for up to two weeks.
After the acute phase, you’ll notice symptoms tapering off. Vomiting usually stops first, followed by a gradual improvement in diarrhea. But “better” doesn’t mean “back to normal.” Many people feel wiped out for several days after the vomiting and diarrhea have stopped. Your gut lining took a hit during the infection, and it needs time to heal. Expect some lingering fatigue, mild nausea, and a sensitive stomach for a few days beyond when the worst symptoms resolve.
When You Can Go Back to Work or School
CDC guidance for schools says students can return once vomiting has resolved overnight and they can hold down food and liquids in the morning. For diarrhea, the threshold is no accidents and no more than two bowel movements above your normal count in a 24-hour period. Most workplaces follow similar logic, even if they don’t have a formal policy.
Keep in mind that you remain contagious beyond when you feel better. You’re most infectious during the acute phase and for a few days after, but you can continue shedding virus in your stool for several weeks after recovery. If you have a weakened immune system or another medical condition, that shedding can last weeks to months. Careful hand-washing after using the bathroom matters long after you feel fine.
What to Eat and Drink During Recovery
Dehydration is the real danger with the stomach flu, not the virus itself. Here’s a general timeline for getting food and fluids back on track:
- First 0 to 6 hours: Stick to ice chips or popsicles. Your stomach needs a break, and sipping water too fast can trigger more vomiting.
- After 6 hours: If vomiting has eased, start sipping clear liquids: water, broth, an electrolyte drink. Small, frequent sips work better than gulping.
- After 24 hours: Try bland, easy-to-digest foods like bananas, rice, applesauce, and toast. These are gentle on an irritated gut.
This timeline is flexible. Some people feel ready for clear liquids within a couple of hours. Others need longer. Follow your body’s signals, and if you can tolerate one step, move to the next. Greasy, spicy, or dairy-heavy foods are worth avoiding for a few days even after you’re eating again, since your digestive system is still recovering.
Signs That Something More Serious Is Happening
For adults, seek medical attention if vomiting lasts more than two days, diarrhea persists beyond several days, or you notice blood in your stool. Dark urine that you’re passing infrequently, dizziness, and lightheadedness are signs of dehydration that mean you’re losing fluids faster than you can replace them.
Children need closer monitoring. Watch for unusual drowsiness, bloody vomit or diarrhea, signs of dehydration like dry mouth, sunken eyes, crying without tears, or diapers that stay dry for more than three hours in infants. A fever above 102°F (39°C) in a child older than 3 months is also a reason to call a doctor. In infants, check whether the soft spot on top of the head looks sunken.
Lingering Digestive Issues After Recovery
For most people, the stomach flu is a miserable few days and then it’s over. But a meaningful minority experience digestive symptoms that drag on much longer than expected. In one study tracking patients for a full year after a bout of gastroenteritis, 32% still had loose stools at the three-month mark, and 12% still had them at one year. About 27% reported recurring abdominal pain at three months, dropping to around 8% at one year.
A small percentage, roughly 2%, go on to develop a condition called post-infectious irritable bowel syndrome, where the infection appears to trigger lasting changes in gut sensitivity and motility. If your digestion still feels off weeks or months after the stomach flu has cleared, that’s not unusual, and it does tend to improve over time. But it’s worth bringing up with a doctor if it’s affecting your daily life, especially if you’re past the three-month mark with no improvement.