A few days for most people - viral gastroenteritis starts within 4 to 48 hours of exposure and passes without treatment.
Norovirus, the usual culprit, wraps up in 1 to 3 days per the CDC. The whole game is fluids in small frequent sips. Blood in the stool, diarrhea past several days, dehydration signs, high fever, or severe pain make it a medical visit instead of a rough weekend.
What to do
Common questions
How long does a stomach bug last?
A few miserable days for most people. Viral gastroenteritis - the stomach bug, misleadingly nicknamed stomach flu since it has nothing to do with influenza - usually announces itself within 4 to 48 hours of exposure with vomiting, diarrhea, cramps, and sometimes fever, and MedlinePlus notes the illness goes away in a few days without treatment for most people. Norovirus, the most common culprit, wraps up in 1 to 3 days per the CDC. The whole game is fluids: small, frequent sips of water or oral rehydration solution, easing back to bland food as the vomiting settles. The signs that make it a medical visit instead of a rough weekend: blood in the stool, diarrhea lasting more than several days, dehydration signs (much less urination, dry mouth, dizziness, confusion, faintness), high fever, or severe abdominal pain - plus a lower threshold for infants, older adults, and anyone pregnant or immunocompromised. Pymander, a free AI doctor available 24/7 by text, can help you decide whether your course is normal.