Most vomiting and diarrhea from a stomach bug clears up on its own in a day or two. Go to the ER if you see blood or coffee-ground material in your vomit, or you have severe belly pain. Also go if you cannot keep fluids down for 12 hours or have not urinated in 8 hours. Black or bloody stools also need care right away. This guide covers every warning sign, how to spot dehydration, and what you can safely do at home.
Most Stomach Bugs Pass on Their Own
A sudden bout of vomiting and diarrhea is usually a viral stomach bug such as norovirus. It feels awful, but most healthy adults recover at home.
The simplest test is whether you can keep enough fluid down to keep urinating. Physicians use that same test.
“Norovirus can last for 24–48 hours. And if you can keep fluids down enough that you can urinate, you can most likely stay at home and let it run its course.”
Joanna Turner Bisgrove, MD, family physician at Rush University Medical Center, in What doctors want patients to know about norovirus
Vomiting: When to Go to the ER
According to MedlinePlus, call 911 or go to the ER right away if:
- You see blood or dark, coffee-colored material in the vomit.
- You think the vomiting is from poisoning.
MedlinePlus also advises getting medical care right away if you have:
- Vomiting for longer than 24 hours
- Not been able to keep any fluids down for 12 hours or more
- Not urinated for 8 hours or more
- Severe stomach or belly pain
- A headache or stiff neck
- Vomited 3 or more times in 1 day
Diarrhea: When to Get Care Right Away
For diarrhea, MedlinePlus advises contacting a provider right away for:
- Blood or pus in your stools
- Black stools
- Stomach pain that does not go away after a bowel movement
- Diarrhea with a fever above 101°F (38.33°C)
- Diarrhea that started after recent travel to a foreign country
- Any signs of dehydration
Diarrhea that gets worse, or does not get better after 5 days in an adult, also needs a provider visit. If a provider is not available, the ER is open at any hour.
Signs of Dehydration in Adults
Dehydration is the main danger of vomiting and diarrhea. Watch for these signs, drawn from MedlinePlus:
- Urinating less often, or dark yellow urine
- Dizziness or lightheadedness
- Dry mouth and increased thirst
- Sunken eyes
- Skin that does not bounce back when you pinch it
Dizziness when you stand, confusion, or no urine for 8 hours means dehydration is getting serious. Our guide to the signs of dehydration covers each one in detail.
“The key thing is hydration. The diarrhea and the vomiting can cause patients who are infected to lose body fluids.”
Robyn F. Chatman, MD, MPH, family physician in Cincinnati, in What doctors want patients to know about norovirus
What Can You Do at Home?
If you have no warning signs, focus on replacing fluids:
- Sip small amounts often. Large gulps can bring the vomiting back.
- Choose drinks with electrolytes. In the AMA interview above, Dr. Chatman recommends non-carbonated electrolyte drinks with no citric acid for mild dehydration.
- Skip caffeine. Dr. Chatman advises against it.
- Avoid cold and flu medicine. She notes it can make you more dehydrated and does not treat a stomach bug.
Keep watching your urine. If it stops, or you cannot keep even small sips down, it is time to get care.
Could It Be Something Other Than a Stomach Bug?
Vomiting and diarrhea usually come from a virus, but not always. Food poisoning can cause the same symptoms, often within hours of a meal.
Belly pain that becomes severe or settles in one spot needs evaluation. Pain that moves to the lower right side can be a sign of appendicitis, which needs emergency care.
What Happens at the ER for Vomiting and Diarrhea?
At ER of Irving, an emergency physician checks how dehydrated you are and looks for a cause. Our on-site lab can check your electrolytes and kidney function during the visit.
If you are dehydrated, IV fluids replace what you have lost faster than drinking can. Imaging is available on site if the physician suspects something like appendicitis.
We are open 24 hours a day at 8200 N MacArthur Blvd, Suite 110, Irving, TX. Walk in any time, or call (972) 893-3148. If there is blood in the vomit or you suspect poisoning, call 911.
FAQs
How long is too long to be throwing up?
MedlinePlus advises getting care if vomiting lasts longer than 24 hours. Get care sooner if you cannot keep fluids down for 12 hours or have not urinated in 8 hours.
Should I go to the ER for vomiting blood?
Yes. Blood or dark, coffee-colored material in the vomit means you should call 911 or go to the ER right away, according to MedlinePlus.
Is diarrhea for 3 days an emergency?
Not by itself. MedlinePlus advises seeing a provider if adult diarrhea does not get better after 5 days. Blood, black stools, a fever above 101°F, or signs of dehydration need care right away at any point.
Can the ER give IV fluids for dehydration?
Yes. IV fluids are one of the most common treatments for dehydration from vomiting and diarrhea. Read more in our guide to IV fluids for dehydration.
When should a child with vomiting go to the ER?
Children dehydrate faster than adults. See our guide to a baby or child who cannot keep liquids down for age-specific warning signs.
Should I go to the ER or urgent care for vomiting and diarrhea?
Mild symptoms without warning signs can be seen at urgent care during open hours. Blood, severe pain, or signs of serious dehydration belong in the ER. Our guide on ER vs. urgent care compares both.
Medically reviewed by the ER of Irving Medical Team | Updated: September 2026
