Diarrhea from a stomach bug typically lasts one to three days, though it can persist for up to two weeks in some cases. Most people feel noticeably better within 72 hours, but the timeline depends on which virus you caught, your age, and your overall health.
Typical Duration by Virus
Norovirus, the most common cause of stomach bugs in adults, tends to resolve quickly. Most people recover within one to three days. Rotavirus, which hits young children hardest, often causes diarrhea that lasts three to eight days. In either case, symptoms can occasionally stretch to 14 days, though that’s uncommon.
The pattern matters as much as the timeline. You should see gradual improvement, with stools becoming less frequent and more formed each day. If diarrhea stays the same or worsens after the first two to three days, that’s worth paying attention to.
Why It Sometimes Lingers
Even after your body clears the virus, your gut lining needs time to heal. The virus damages the cells lining your small intestine, and until those cells regenerate, digestion doesn’t work at full capacity. This is why you might still have loose stools or mild cramping for several days after the worst symptoms pass.
One common aftereffect is temporary lactose intolerance. Viruses like rotavirus damage the part of the intestinal lining that produces the enzyme needed to break down lactose, the sugar in milk and dairy products. This means dairy can trigger bloating, gas, and more diarrhea even after you’re otherwise recovered. The intolerance typically resolves within three to four weeks as the intestinal lining repairs itself. If you notice that dairy seems to make things worse during recovery, switching to lactose-free options for a few weeks can help.
Post-Infectious Bowel Changes
A small percentage of people develop lasting changes in bowel habits after a stomach bug. This condition, called post-infectious irritable bowel syndrome, involves recurring diarrhea, cramping, or bloating that starts after an episode of gastroenteritis in people who had no prior bowel issues. Symptoms can persist for months. If your diarrhea clears up after the acute illness but then returns in an on-and-off pattern weeks later, this may be what’s happening.
What to Eat During Recovery
The old advice to stick to bananas, rice, applesauce, and toast (the BRAT diet) is outdated. The American Academy of Pediatrics no longer recommends it for children because it’s too restrictive and lacks the nutrients your gut needs to heal. For adults, those bland foods are fine for the first day or so when you’re at your sickest, but sticking with them longer than 24 hours can actually slow recovery.
As soon as you feel able to eat more, you should. Your body needs protein, fiber, and vitamins like B12 and calcium to rebuild the intestinal lining and regain strength. Soft, easy-to-digest foods like cooked vegetables, lean chicken, eggs, and oatmeal are good next steps. Reintroduce foods gradually, but don’t stay on a starvation-level diet out of caution. Eating helps your gut recover faster.
How Long You’re Contagious
Your diarrhea may be gone, but you’re not necessarily safe to be around others. With norovirus, you can continue shedding the virus for two weeks or more after you feel better. The CDC recommends staying home for at least 48 hours after your last episode of diarrhea or vomiting. This is especially important if you work with food, care for young children, or spend time around elderly or immunocompromised people.
Thorough handwashing with soap and water is more effective than hand sanitizer against norovirus. Alcohol-based sanitizers don’t kill it reliably.
Warning Signs That Need Attention
Most stomach bugs are miserable but harmless. However, certain symptoms signal that something more serious is going on or that dehydration is becoming dangerous.
For adults, contact a doctor if you experience:
- Diarrhea lasting more than two days
- Six or more loose stools per day
- High fever
- Blood, pus, or black tarry color in your stool
- Severe abdominal or rectal pain
- Signs of dehydration like dark urine, dizziness, or extreme thirst
For children, the timeline is shorter. Diarrhea lasting more than one day in a child warrants a call to the pediatrician. Any fever in an infant is a reason to seek help, along with refusing to eat or drink for more than a few hours. Watch for no wet diapers for three or more hours, no tears when crying, a sunken soft spot on the skull, or unusual drowsiness. These are signs of dehydration that need prompt attention, especially in babies under 12 months or those born prematurely.
Dehydration is the real danger with stomach bugs, not the infection itself. Small, frequent sips of water or an oral rehydration solution do more good than trying to drink large amounts at once, which can trigger more vomiting.