Most stomach bugs cause vomiting that lasts 1 to 3 days. Norovirus, the most common cause, typically runs its course within that window, with the worst vomiting often concentrated in the first 12 to 24 hours. Rotavirus infections can drag on longer, with vomiting and diarrhea lasting 3 to 8 days, especially in young children.
The Typical Timeline
A stomach bug follows a fairly predictable pattern. After exposure, you won’t feel anything for 12 to 48 hours. Then symptoms hit fast, often starting with nausea and vomiting before diarrhea kicks in. That initial wave of vomiting is usually the most intense part of the illness, and for many people it’s the shortest phase. You may vomit repeatedly for several hours, then notice the episodes spacing out over the next day or two.
For norovirus, which causes the majority of stomach bugs in adults, the entire illness (vomiting, diarrhea, and body aches combined) lasts 1 to 3 days. The vomiting itself often fades before the diarrhea does, so you might stop throwing up after the first day but still have loose stools for another day or two. Rotavirus tends to be more drawn out, particularly in babies and toddlers, where vomiting and watery diarrhea can persist for 3 to 8 days.
What to Do While You’re Still Vomiting
The biggest risk during a stomach bug isn’t the virus itself. It’s dehydration. Every time you vomit, you lose fluids and electrolytes your body needs. The challenge is that drinking too soon after throwing up can trigger another episode, so timing matters.
Wait 30 to 60 minutes after your last vomit before trying to sip clear liquids. Start small: a few sips of water, an oral rehydration solution, or clear broth. If that stays down for 15 to 20 minutes, take a few more sips. The goal is slow, steady intake rather than gulping a full glass, which your stomach will likely reject. Popsicles and ice chips work well for kids who refuse to sip from a cup.
When to Start Eating Again
Once you’ve kept liquids down for several hours without vomiting, you can try solid food. The classic advice is the BRAT diet (bananas, rice, applesauce, toast), and those foods are fine for a day or two. But there’s no medical reason to limit yourself to just those four items. Brothy soups, oatmeal, boiled potatoes, crackers, and unsweetened dry cereal are all easy on a recovering stomach.
As you feel better, add foods with more nutritional value: cooked carrots, sweet potatoes without skin, avocado, skinless chicken, fish, or eggs. These are still bland and easy to digest, but they provide the protein and nutrients your body needs to actually recover. Restricting yourself to plain toast for days on end can slow that process down.
Signs That Something More Serious Is Happening
A stomach bug that follows the normal 1 to 3 day pattern, while miserable, resolves on its own. Your immune system clears the virus without any medication. But certain warning signs mean you should contact a doctor:
- Vomiting or diarrhea lasting more than two days in an adult
- Inability to keep any liquids down for 24 hours
- Signs of dehydration: very dark urine, little or no urination, excessive thirst, dry mouth, dizziness, or severe weakness
- Blood in your vomit or stool
- Severe stomach pain (beyond the typical cramping)
- Fever above 104°F (40°C)
Children need closer monitoring. See a doctor if a child has a fever above 102°F, seems unusually tired or irritable, has bloody diarrhea, or shows signs of dehydration like a dry mouth, no tears when crying, or unusual sleepiness. For infants specifically, no wet diaper in six hours is a red flag, as is a sunken soft spot on the head.
You’re Still Contagious After You Feel Better
One detail that catches people off guard: you can still spread the virus after your symptoms stop. Norovirus continues to shed in stool for days after you feel fine. This is why handwashing matters so much during recovery, not just during the worst of the illness. Avoid preparing food for others for at least two days after your last symptoms, and clean any contaminated surfaces with a bleach-based cleaner, since alcohol-based sanitizers don’t reliably kill norovirus.