A stomach virus typically lasts 1 to 3 days in most adults, though some cases stretch to 8 days depending on the specific virus involved. The two most common culprits, norovirus and rotavirus, follow different timelines and hit different age groups hardest.
How Long Each Virus Lasts
Norovirus is the most frequent cause of stomach illness in adults, and it moves fast. Symptoms hit hard but clear quickly. Most people feel better within 1 to 2 days of symptoms starting. The illness often peaks within the first 12 to 24 hours with intense vomiting and watery diarrhea, then tapers off.
Rotavirus lasts longer. Symptoms typically appear about 2 days after exposure and persist for 3 to 8 days. Rotavirus is especially common in young children, who tend to experience the full range of that timeline. Adults who catch rotavirus generally have milder, shorter episodes because most have some immunity from childhood exposure.
From Exposure to First Symptoms
After you’re exposed to norovirus, there’s a window of 12 to 48 hours before you feel anything. This incubation period is one reason stomach viruses spread so efficiently: you can pass the virus to others before you even realize you’re sick. Rotavirus has a similar lag, with symptoms showing up roughly 1 to 3 days after contact.
The first sign is usually nausea, followed quickly by vomiting. Watery diarrhea, stomach cramps, and sometimes a low-grade fever develop within hours of that initial wave. The vomiting phase tends to be shorter than the diarrhea phase. Many people stop vomiting within 24 hours but continue having loose stools for another day or two.
How Long You Stay Contagious
This is where the timeline gets tricky. You feel better long before you stop shedding the virus. Research on norovirus found that people continued shedding detectable virus in their stool for a median of 7 to 10 days after infection, with some individuals shedding virus particles for several weeks. The practical takeaway: even after your symptoms resolve, you’re still capable of spreading the illness for days.
Hand hygiene matters most during this extended window. Alcohol-based hand sanitizers are less effective against norovirus than thorough soap-and-water handwashing, which is worth knowing since the contagious period outlasts symptoms by so long.
Dehydration Is the Real Risk
The stomach virus itself isn’t dangerous for most healthy adults. Dehydration is. When you’re losing fluids from both ends for 24 to 48 hours, your body can fall behind quickly. Infants and young children are particularly vulnerable. Newborns and infants can become severely dehydrated in just a day or two of diarrhea.
In babies, watch for fewer wet diapers than usual, or no wet diapers for 3 hours or more. Other signs of dehydration at any age include dark urine, dry mouth, dizziness when standing, and crying without tears in young children. Small, frequent sips of water, broth, or an oral rehydration solution work better than trying to drink large amounts at once, which can trigger more vomiting.
What to Eat During Recovery
Most experts no longer recommend fasting or following a restricted diet like the old BRAT diet (bananas, rice, applesauce, toast) during a stomach virus. The current guidance is simpler: eat your normal diet as soon as your appetite returns, even if you still have some diarrhea. The same applies to children. Give them whatever they usually eat once they’re willing to eat again.
Your appetite will likely return before your digestion fully normalizes. Some people notice looser stools or mild bloating for a few days after the worst has passed. This is normal and doesn’t mean the virus is still active. Temporarily reducing greasy, spicy, or high-fiber foods can help if your stomach still feels sensitive, but there’s no strict recovery diet you need to follow.
When to Return to Work or School
CDC guidance for schools recommends that children stay home until vomiting has resolved overnight and they can hold down food and liquids the next morning. For diarrhea, bowel movements should be no more than 2 above the child’s normal frequency in a 24-hour period. If there was a fever, the child should be fever-free for at least 24 hours without medication.
The same general rules apply to adults returning to work, though workplace policies vary. Given that you remain contagious after symptoms stop, careful handwashing for at least a few days after you feel well is important, especially if you work with food, in healthcare, or around young children or elderly people.
When Symptoms Last Too Long
A stomach virus that doesn’t improve within 7 days is worth investigating. Persistent diarrhea at that point could signal a bacterial infection or another cause that needs different treatment. If diarrhea continues for 14 days or more, parasitic infections become a more likely explanation, though they account for fewer than 5% of acute gastroenteritis cases overall.
Bloody stool, a fever above 102°F (39°C), or an inability to keep any fluids down for more than 24 hours are signs that something beyond a typical stomach virus may be happening. For infants, elderly adults, or anyone with a weakened immune system, these thresholds are lower. Dehydration develops faster and hits harder in these groups, and medical attention sooner rather than later makes a significant difference.