Most stomach bugs last 1 to 3 days, though some can stretch to 8 days or longer depending on the cause. The vast majority of cases are viral, and you’ll typically feel noticeably better within 72 hours of your first symptoms. Bacterial infections can take longer, and some post-illness gut sensitivity lingers for weeks after the main illness clears.
Viral Stomach Bugs: 1 to 8 Days
Norovirus is the most common culprit in adults, while rotavirus is more frequent in young children. Both follow a similar pattern: symptoms appear roughly 1 to 2 days after exposure, peak within the first 24 to 48 hours, then taper off. Rotavirus specifically causes vomiting and watery diarrhea lasting 3 to 8 days, while norovirus tends to resolve a bit faster, often within 1 to 3 days.
The worst of it, the intense vomiting and inability to keep anything down, usually passes within 24 hours. Diarrhea tends to hang around a day or two longer than the vomiting does. You may also feel wiped out and have low energy for several days after the vomiting and diarrhea stop, which is normal and mostly reflects dehydration and the toll the illness took on your body.
Bacterial Infections Take Longer
If your stomach bug came from contaminated food rather than contact with a sick person, bacteria may be the cause. These infections generally last longer than viral ones:
- Salmonella: 2 to 7 days
- Campylobacter: 5 to 7 days
- E. coli: 3 to 6 days
- Shigella: 2 to 7 days
Some bacterial infections are shorter. Food poisoning from staph toxins, for instance, hits hard but typically clears within a single day because it’s caused by a toxin already in the food rather than an active infection in your gut. If your symptoms started within 6 hours of eating something suspicious and cleared within 24 hours, a preformed toxin was likely the cause.
Why Your Gut Feels Off After You “Recover”
Even after the vomiting and diarrhea are gone, your digestive system often needs more time to fully reset. Loose stools, mild bloating, and sensitivity to certain foods can continue for a week or two. Dairy is a common trigger during this window. Some people temporarily lose the ability to digest lactose well, and this can persist for a month or more after the infection clears.
A small but notable percentage of people, somewhere between 7% and 33% in studies of bacterial gastroenteritis, develop longer-lasting irritable bowel symptoms: cramping, irregular bowel habits, and bloating that persists for months. A six-year follow-up study found that roughly half of these people eventually recovered fully, but for others it became a chronic issue. This doesn’t mean a stomach bug will ruin your gut permanently, but if your digestion still feels off several weeks later, that’s a recognized pattern and not something you’re imagining.
You’re Still Contagious After You Feel Better
This catches most people off guard. With norovirus, you can continue spreading the virus for two weeks or more after your symptoms have completely resolved. The highest risk of transmission is during the illness itself and the first few days after recovery, but viral particles keep shedding in stool for much longer. Thorough hand washing, especially after using the bathroom, matters well beyond the point where you feel fine again.
Eating and Drinking During Recovery
Staying hydrated is the single most important thing you can do while sick. Small, frequent sips of water or an oral rehydration solution work better than trying to gulp large amounts at once, which can trigger more vomiting. Commercial rehydration drinks are preferable to homemade salt-and-sugar mixtures, since getting the proportions wrong can actually make things worse.
Once your appetite starts returning, you can go back to your normal diet. Most experts do not recommend fasting or following a restricted diet during a stomach bug. The old advice about eating only bland foods has fallen out of favor. That said, a few things tend to make lingering diarrhea worse: caffeinated drinks, high-fat or fried foods, very sugary beverages, and dairy products. You don’t need to avoid these strictly, but if diarrhea is still an issue, cutting back on them for a few days may help.
Signs the Illness Needs Medical Attention
Most stomach bugs resolve on their own, but dehydration is a real risk, especially at the extremes of age. In adults, diarrhea lasting more than two days, a high fever, blood or pus in stools, severe abdominal pain, or six or more loose stools per day all warrant a call to your doctor. The same applies if you simply can’t keep enough fluids down to stay hydrated. Signs of dehydration include dark urine, urinating much less than usual, extreme thirst, dizziness, and sunken-looking eyes.
For infants and young children, the thresholds are lower. Diarrhea lasting more than one day, any fever in infants, no wet diapers for three hours or more, or crying without tears are all reasons to seek help promptly. Older adults, pregnant women, and anyone with a weakened immune system should also get medical attention early rather than waiting it out.