Viral Gastroenteritis: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Viral Gastroenteritis?
It is an infection of the intestines that people often call the stomach flu. A primary care doctor can usually diagnose and treat it. A gastroenterologist, a doctor who treats digestive diseases, can help if symptoms are severe. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is viral gastroenteritis?
People often call it the stomach flu, but flu viruses do not cause it. In most cases, it is not harmful. It can become dangerous if it leads to dehydration.
Symptoms
The symptoms include:
- Watery diarrhea.
- Pain or cramping in the belly.
- Nausea or vomiting.
- Sometimes a fever.
Dehydration is the most common complication of viral gastroenteritis. Signs in adults include extreme thirst, dry mouth, urinating less than usual, dark-colored urine, and feeling tired. In a baby or young child, watch for no wet diapers for 3 hours or more, no tears when crying, and a dry mouth.
Causes and who gets it
Many different viruses can cause it. Norovirus is the most common cause. It infects people of all ages. Rotavirus, adenovirus, and astrovirus most often infect infants and young children, but adults can get them too. The illness spreads from person to person through contact with an infected person's stool or vomit.
You can spread the virus if you do not wash your hands well after using the bathroom. Norovirus is especially contagious. It can live for months on surfaces such as countertops and changing tables.
Some people are at higher risk of serious problems. They include pregnant women, older adults, and infants. They also include people with weakened immune systems or other serious health conditions.
How doctors diagnose it
Your provider will do a physical exam and ask about your symptoms. Your provider may also test a stool sample. Bacteria, parasites, and chemicals can cause other kinds of gastroenteritis.
Treatment
Most people get better on their own without medical treatment. Treatment means replacing lost fluids and electrolytes so that you do not become dehydrated. Most adults can do this with water, fruit juices, sports drinks, or broths. If vomiting is a problem, try sipping small amounts of clear liquids.
If your child is sick with it, give your child an oral rehydration solution as directed. Infants should drink breast milk or formula as usual, and a doctor can advise about rehydration solutions.
When your appetite returns, you can most often go back to eating your normal diet, even if you still have diarrhea.
Adults can sometimes take over-the-counter medicines such as loperamide or bismuth subsalicylate for diarrhea. These medicines can be unsafe for infants and children. Do not use them if you have bloody diarrhea or fever, and see a doctor instead.
A doctor may prescribe medicine to control severe vomiting. Doctors do not prescribe antibiotics, because antibiotics do not work for viral infections. A doctor may suggest probiotics, which are live microbes like the ones in your digestive tract. Some probiotics may help shorten a case of diarrhea.
To help prevent it, wash your hands with soap and water. Do this after using the bathroom, after changing diapers, and before and after handling, preparing, or eating food. If you are sick, avoid preparing food for others while you are sick and for 2 days after your symptoms stop. There are vaccines that protect infants against rotavirus infections.
When to see a doctor
See a doctor right away if you have signs of dehydration. Adults should also see a doctor right away if they have any of these:
- A change in mental state, such as irritability or lack of energy.
- Diarrhea lasting more than 2 days.
- High fever.
- Vomiting often.
- Six or more loose stools in a day.
- Severe pain in the belly or rectum.
- Black, tarry stools, or stools that contain blood or pus.
Older adults, pregnant women, and people with a weak immune system or other health problems should see a doctor right away for any symptoms.
Diarrhea is especially dangerous in newborns and infants. It can cause severe dehydration in just a day or two.
Call 911 or go to the emergency room if the person faints or loses consciousness. Do the same for severe confusion, trouble waking up, or vomiting blood.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A direct primary care or concierge doctor can ask about your symptoms, do a physical exam, and tell you when you need more urgent care.
Common questions
Is viral gastroenteritis the same as the flu?
No, flu viruses do not cause it, even though people call it the stomach flu. Flu viruses infect the respiratory system, while viral gastroenteritis is an infection of the intestines.
How long does viral gastroenteritis last?
With norovirus, the most common cause, it lasts about 1 to 3 days. Other viruses can last longer, such as 3 to 8 days for rotavirus and 1 to 2 weeks for adenovirus.
How does viral gastroenteritis spread?
It spreads from person to person through contact with an infected person's stool or vomit. You can spread it if you touch surfaces, prepare food, or shake hands without washing your hands well.
Do antibiotics help viral gastroenteritis?
No, antibiotics do not help, because they do not work for viral infections.
Sources
- National Institute of Diabetes and Digestive and Kidney Diseases - Symptoms & Causes of Viral Gastroenteritis ("Stomach Flu")
- National Institute of Diabetes and Digestive and Kidney Diseases - Treatment of Viral Gastroenteritis ("Stomach Flu")
- MedlinePlus - Gastroenteritis
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
