Most stomach bugs last one to three days, with symptoms peaking on the first day and tapering off quickly after that. In severe cases, symptoms can linger for up to a week or two, but the majority of healthy adults recover within a few days without medical treatment.
Typical Duration by Cause
The timeline depends on which virus or bacteria is responsible. Norovirus, the most common cause of stomach bugs in adults, produces symptoms that last one to three days. Rotavirus, which more commonly affects young children, tends to hang on longer, lasting three to eight days. Bacterial causes like salmonella or campylobacter fall somewhere in that range as well, with most mild cases of gastroenteritis resolving within one to seven days regardless of the specific germ involved.
You won’t always know which pathogen you picked up, and you usually don’t need to. The practical difference is small for most people: expect to feel miserable for a day or two, then gradually improve over the next couple of days after that.
How Symptoms Unfold
Symptoms typically appear 12 to 48 hours after you’re exposed to the virus. For many people, the onset feels sudden. You might go from feeling completely fine to vomiting or having diarrhea multiple times within a few hours.
The first day is almost always the worst. Vomiting tends to hit hardest in the first 12 to 24 hours and usually stops before the diarrhea does. Diarrhea, nausea, stomach cramps, and sometimes a low-grade fever can persist for another day or two after the vomiting subsides. Some people also experience body aches, headache, and fatigue that linger even after the gut symptoms have cleared.
By day two or three, most people notice a clear turning point where they can keep fluids down and the trips to the bathroom slow significantly. Full energy and appetite can take a few extra days to return, even after the active symptoms are gone.
How Long You’re Contagious
This is the part that surprises most people. You can still spread norovirus for two weeks or more after you feel better. The virus continues shedding in your stool long after your symptoms resolve, which is why stomach bugs tear through households, schools, and workplaces so effectively.
Thorough handwashing with soap and water (not just hand sanitizer, which is less effective against norovirus) is the single most important step during those post-recovery weeks. Avoid preparing food for others if possible during the first few days after recovery, and disinfect bathroom surfaces frequently.
Staying Hydrated During Recovery
Dehydration is the main medical risk from a stomach bug, not the infection itself. When you’re losing fluids from both ends, replacing them matters more than eating. Take small sips of water or suck on ice chips, even if you can’t keep much down at first. Broth, popsicles, diluted fruit juice (half water, half juice), and weak decaffeinated tea are also good options.
Skip sports drinks like Gatorade if you’re significantly dehydrated. They don’t contain the right balance of sugar and sodium. Oral rehydration solutions like Pedialyte work better because they’re specifically formulated for fluid replacement. You can also make your own by mixing four cups of water with half a teaspoon of salt and two tablespoons of sugar.
What to Eat as You Recover
The classic BRAT diet (bananas, rice, applesauce, toast) is fine for the first day or two, but there’s no reason to limit yourself to just those four foods. Brothy soups, oatmeal, boiled potatoes, crackers, and unsweetened dry cereal are equally easy on your stomach. The goal is bland, simple foods that won’t irritate your digestive system while it heals.
Once the worst has passed and your stomach feels more settled, gradually add more nutritious foods: cooked squash, carrots, sweet potatoes without the skin, avocado, skinless chicken or turkey, fish, and eggs. Avoid alcohol, caffeine, dairy, fried foods, spicy foods, and anything high in sugar or acidity until you’re fully back to normal. Raw vegetables, leafy greens, popcorn, nuts, and seeds are also best saved for later since their insoluble fiber can aggravate a recovering gut.
Signs That Something More Serious Is Happening
Most stomach bugs resolve on their own, but certain warning signs suggest you need medical attention. Diarrhea that hasn’t improved after seven days warrants a visit, as it may point to something beyond a typical viral infection. Bloody or bilious (green-tinged) vomit, a fever above 104°F, or signs of significant dehydration like dizziness, very dark urine, or not urinating at all for many hours are all reasons to seek care promptly.
Young children, especially those under six months, are at higher risk for dangerous dehydration. In infants and toddlers, watch for excessive irritability, no tears when crying, a sunken soft spot on the head, or poor skin color. Older adults and people with weakened immune systems also face greater risk and may take longer to recover. For these groups, a shorter leash on seeking medical help is reasonable.