Most stomach bugs last 1 to 3 days in otherwise healthy adults. The exact timeline depends on which virus or bacteria caused the infection, but the worst of it, the vomiting and watery diarrhea, typically peaks within the first 24 hours and tapers off from there.
Timeline by Type of Infection
The most common stomach bug by far is norovirus. Symptoms show up 12 to 48 hours after exposure and resolve within 1 to 3 days. For most people, day two is the turning point where vomiting stops and diarrhea begins to slow down.
Rotavirus tends to hit harder and linger longer, especially in young children. Vomiting and watery diarrhea from rotavirus can last 3 to 8 days, making dehydration a bigger concern.
If the cause is bacterial rather than viral, expect a longer recovery. Salmonella infections last 4 to 7 days. E. coli typically takes 5 to 10 days to clear, though most people feel significantly better by day five. Bacterial infections often come from undercooked meat, contaminated produce, or improperly stored food, while viral stomach bugs spread person to person or through contaminated surfaces.
How to Tell a Virus From Food Poisoning
The timing gives you the biggest clue. A viral stomach bug usually starts with nausea and vomiting, then transitions to diarrhea over the next day or two. It often shows up a day or two after you were around someone who was sick. Bacterial food poisoning tends to come on faster after eating a specific meal, and diarrhea is usually the dominant symptom from the start. Bacterial infections also produce higher fevers and can cause bloody stools, which are uncommon with a standard viral stomach bug.
Why You Still Feel Off After the Bug Is Gone
Even after the vomiting and diarrhea stop, many people notice lingering digestive symptoms for days or weeks: bloating, loose stools, cramping after meals, or a reduced appetite. This is normal. Your gut lining took a hit and needs time to rebuild.
In about 1 in 10 people who get a gut infection, those lingering symptoms develop into something called post-infectious irritable bowel syndrome. This means ongoing cramping, diarrhea, or irregular bowel movements that persist well beyond the original illness. It’s common for this to last for years. Roughly half of cases resolve on their own within six to eight years. If your digestive symptoms haven’t returned to normal several weeks after your stomach bug, that pattern is worth bringing up with your doctor.
How Long You Stay Contagious
This is where people often get tripped up. You feel better, so you assume you’re no longer spreading the virus. With norovirus, you continue shedding the virus in your stool for days after symptoms resolve, sometimes up to two weeks. The highest risk of spreading it is during the illness itself and in the first 48 hours after symptoms stop. Thorough handwashing with soap and water (not just hand sanitizer, which doesn’t kill norovirus effectively) is the most reliable way to avoid passing it on.
Eating During Recovery
You may have heard of the BRAT diet (bananas, rice, applesauce, toast) as the go-to recovery plan. Current evidence doesn’t support it. The old idea of “resting” your gut by restricting food has been replaced by research showing the opposite: eating a normal, balanced diet as soon as you can tolerate it leads to less diarrhea, shorter illness, and better nutritional recovery. Restrictive diets during a stomach bug can actually slow healing and, in children especially, contribute to nutritional deficits.
Start with whatever sounds manageable. Small, frequent meals tend to be easier to keep down than large ones. Stay hydrated with water, broth, or an oral rehydration solution, particularly if diarrhea has been heavy. Avoid alcohol and caffeine until you’re fully recovered, since both can worsen dehydration.
Warning Signs That Need Medical Attention
Most stomach bugs resolve without any treatment. But dehydration can become dangerous quickly, especially in young children and older adults. In adults, contact a healthcare provider if you experience:
- Diarrhea lasting more than 2 days
- Six or more loose stools in a single day
- High fever
- Severe abdominal pain
- Black, tarry, or bloody stools
- Signs of dehydration: dark urine, dry mouth, dizziness, or urinating much less than usual
For infants and young children, the thresholds are lower. Diarrhea lasting more than a day, any fever in infants, no wet diapers for 3 or more hours, or no tears when crying all warrant a call to your pediatrician. Children dehydrate faster than adults, and what looks like a routine bug can escalate quickly in small bodies.