Most adults recover from a stomach bug within one to three days. Symptoms like vomiting, diarrhea, and stomach cramps typically hit hard and fast, then taper off relatively quickly. The exact timeline depends on which virus or bacteria caused the infection, your overall health, and how well you stay hydrated during the worst of it.
Symptom Timeline From Exposure to Recovery
The clock starts ticking well before you feel sick. After exposure to norovirus, the most common cause of stomach bugs in adults, symptoms appear 12 to 48 hours later. That gap explains why you often can’t pinpoint exactly where you caught it.
Once symptoms begin, they tend to follow a predictable arc. The first 12 to 24 hours are usually the most intense, with frequent vomiting and watery diarrhea. By day two, vomiting often slows or stops, though diarrhea and nausea can linger. Most people feel noticeably better by day three, though low energy and a sensitive stomach can hang around for several more days as your gut finishes healing.
Even after the worst symptoms are gone, you’re not immediately back to normal. It’s common to feel washed out, mildly bloated, or have loose stools for up to a week. This doesn’t mean you’re still sick. Your intestinal lining took a hit and needs time to fully recover.
Why Some Stomach Bugs Last Longer
Not every stomach bug runs on the same schedule. Norovirus infections are typically the shortest, resolving in one to three days. Bacterial infections from Salmonella or Campylobacter, often picked up from undercooked poultry or contaminated food, can cause diarrhea that persists for a week or more. These infections tend to come with higher fevers and sometimes bloody stool, which helps distinguish them from a standard viral stomach bug.
Your age and baseline health matter too. Older adults and people with weakened immune systems often experience longer, more severe episodes. Dehydration can also extend recovery. When your body loses fluid faster than you can replace it, healing slows and symptoms feel worse.
How Long You Stay Contagious
You’re most contagious while you have active symptoms, but the risk doesn’t end the moment you stop vomiting. With norovirus, viral particles continue to shed in your stool for days after you feel better. Most guidelines recommend staying home for at least 48 hours after your last episode of vomiting or diarrhea. During this window, thorough handwashing with soap and water is more effective than hand sanitizer, since alcohol-based products don’t kill norovirus as reliably.
Staying Hydrated During the Worst of It
Dehydration is the main risk with any stomach bug. When you’re losing fluid from both ends, replacing water alone isn’t enough. You need electrolytes and a small amount of sugar to help your body actually absorb the fluid.
You can make a simple rehydration drink at home: combine four cups of water with half a teaspoon of table salt and two tablespoons of sugar. Sip it slowly rather than gulping, especially if you’re still vomiting. Another option is mixing two cups of regular chicken broth (not low sodium) with two cups of water and two tablespoons of sugar. Commercial electrolyte drinks work too, though many contain more sugar than you need.
The key is small, frequent sips. If you try to drink a full glass at once on an irritated stomach, it’s likely to come right back up. A few tablespoons every 10 to 15 minutes is a better approach during the acute phase.
Signs of Dangerous Dehydration
Most stomach bugs are unpleasant but not dangerous. However, dehydration can escalate quickly if you can’t keep any fluids down. Watch for these warning signs: a rapid heartbeat (over 100 beats per minute at rest), significant dizziness or lightheadedness, very little urine output or dark-colored urine, confusion or extreme drowsiness, and muscle cramping. If you’re unable to keep fluids down for more than 12 to 24 hours, that’s a signal you may need medical help to rehydrate.
What to Eat as You Recover
The old advice to stick strictly to bananas, rice, applesauce, and toast (the BRAT diet) has fallen out of favor. While those foods are gentle on the stomach, the diet lacks protein, calcium, fiber, and key vitamins your body needs to recover. Following it for more than a day or two can actually slow your healing.
The current approach is simpler: eat as tolerated. While you’re actively vomiting, stick to clear liquids. Once the vomiting stops, start with small, bland meals. Scrambled eggs, skinless chicken, cooked vegetables, and plain crackers are all good early choices. Your stomach handles smaller portions better during recovery, so five or six mini-meals throughout the day will sit easier than three large ones. Rich, greasy, or heavily spiced foods are worth avoiding until your digestion feels stable, which usually takes a few days beyond the point where vomiting and diarrhea stop.
Lingering Gut Issues After Recovery
About 1 in 10 people who get a gut infection develop a condition called post-infectious irritable bowel syndrome. This can cause recurring bouts of cramping, bloating, diarrhea, or constipation that persist for weeks or months after the original infection has cleared. It happens because the infection temporarily alters the gut’s nerve sensitivity and the balance of bacteria in the intestines.
If your stomach still doesn’t feel right several weeks after a stomach bug, especially if you’re noticing patterns like cramping after meals or alternating diarrhea and constipation, it’s worth getting evaluated. Post-infectious gut issues are common, treatable, and not a sign that you’re still infected.