Most stomach bugs last 1 to 3 days, though some can stretch to a week depending on the cause. The worst symptoms, vomiting and diarrhea, typically peak within the first 24 to 48 hours and then gradually ease. Even after you feel better, you can remain contagious for days or even weeks.
Typical Duration by Cause
The most common stomach bug is norovirus, which accounts for the majority of viral gastroenteritis cases in adults. Most people with norovirus feel better within 1 to 3 days. Symptoms usually appear 24 to 48 hours after exposure, so the entire experience from first contact to recovery is roughly 3 to 5 days.
Rotavirus, which is more common in young children, follows a similar pattern but can last slightly longer, particularly in kids who haven’t been vaccinated. Bacterial infections that people often lump in with “stomach bugs” tend to drag on longer. A Campylobacter infection, for instance, typically makes people sick for 5 to 7 days, with symptoms showing up 2 to 5 days after exposure.
Stomach Bug vs. Food Poisoning
The biggest clue is timing. A viral stomach bug has a 24 to 48 hour incubation period before symptoms start. Food poisoning hits much faster, usually within 2 to 6 hours of eating contaminated food. Food poisoning also tends to resolve more quickly, often burning through your system in under a day. A viral stomach bug generally lingers for about two days, sometimes longer.
If symptoms came on suddenly after a specific meal and cleared within hours, food poisoning is the more likely culprit. If they crept in a day or two after being around someone who was sick, you’re probably dealing with a virus.
How Long You Stay Contagious
This is the part most people underestimate. With norovirus, you can still spread the virus for 2 weeks or more after your symptoms are gone. The virus continues to shed in stool long after you feel fine. People with rotavirus are contagious even before symptoms appear and remain so for up to two weeks after recovery.
This means the window where you can infect others is far wider than the window where you actually feel sick. Careful hand washing, especially after using the bathroom, matters long after the vomiting stops.
How Stomach Bugs Affect Children
Kids, especially babies and toddlers, tend to get hit harder and are more vulnerable to dehydration. Their smaller bodies lose fluid faster, and they may not be able to communicate how they feel or drink enough to keep up.
Signs of dehydration to watch for in babies include a sunken soft spot on the top of the head, few or no tears when crying, fewer wet diapers than usual, and unusual drowsiness or irritability. In older children and adults, warning signs include dark yellow urine, peeing less often, dizziness when standing, and feeling unusually tired.
For children, diarrhea lasting more than a day warrants a call to a doctor. Any fever at all in infants is a reason to seek medical help. For adults, the threshold is a bit higher: diarrhea lasting more than 2 days, six or more loose stools in a single day, a high fever, severe abdominal pain, or blood in the stool all signal that something more serious may be going on.
What Recovery Looks Like
The first priority is getting through the vomiting phase without pushing food or drink too aggressively. Once vomiting stops, start with ice chips or a popsicle for the first several hours. After about 6 hours, try sipping clear liquids like water, broth, or an oral rehydration solution and see how your stomach handles it.
After 24 hours of keeping liquids down, you can move to bland, easy-to-digest foods. Toast, rice, bananas, and applesauce are the classic choices. Avoid dairy, fatty foods, caffeine, and alcohol until your gut has had a few days to settle. Most people can return to their normal diet within 3 to 5 days of symptom onset, though some notice lingering sensitivity for a bit longer.
Rehydration is the single most important thing you can do. The vomiting and diarrhea themselves aren’t usually dangerous. The dehydration they cause is what leads to complications, particularly in very young children and older adults.
Timeline at a Glance
- Exposure to first symptoms: 24 to 48 hours for most viral stomach bugs
- Active illness: 1 to 3 days for norovirus, up to 7 days for bacterial infections
- Contagious period: up to 2 weeks or more after symptoms resolve
- Return to normal eating: typically 3 to 5 days from symptom onset