Table of ContentsView AllTable of ContentsFrequent SymptomsComplicationsWhat to DoWhen to See a Healthcare ProviderFrequently Asked QuestionsNext in Stomach Flu GuideHow Stomach Flu Is Diagnosed
Table of ContentsView All
View All
Table of Contents
Frequent Symptoms
Complications
What to Do
When to See a Healthcare Provider
Frequently Asked Questions
Next in Stomach Flu Guide
Viral gastroenteritis, commonly known as thestomach fluor a stomach bug, is a highlycontagiousillness that causes vomiting, diarrhea, abdominal pain, and weakness, among other possible and very uncomfortable symptoms.
For most healthy adults, it is short-lived and without consequence. However, it’s important to watch forsymptoms of dehydration, especially in children and the elderly, as excessive fluid loss can occur as the result of the stomach flu.
Rotavirus, sapoviruses, astroviruses, and adenoviruses are most likely to infect children under 5 years old, butnoroviruscommonly infects people of all ages.Luckily, there is now an oral vaccine for rotavirus in babies, so infection is not as common as it used to be.
What’s certain is that the stomach flu is contagious, as are most other illnesses with diarrhea and vomiting. To understand the risks to yourself and to others, it’s important to know the signs of stomach flu.
Depending on the virus that is causing the infection, the onset after exposure and the duration of illness can vary.Norovirusis the most common cause of viral gastroenteritis. Symptoms usually begin 12 to 48 hours after exposure to the virus, and illness lasts one to three days.
For the other viruses, onset is from two to 10 days after exposure, and illness can last anywhere from a day to two weeks.
Typically, the stomach flu is a “self-limiting” illness, which meansit will go awayon its own after a few days, though it may linger in some instances. Symptoms of stomach flu may include:
Compared to Food Poisoning
When people talk about “food poisoning,” they are often thinking of bacterial infections likeSalmonellaorE. coli,which are transmitted through meat, eggs, cheese, or produce, causing largeoutbreaks and food recalls.
These germs are less common, but are more likely to lead to hospitalization and long-term health effects:
Unfortunately, there is no good way to know at first which germ is making you sick. Symptom onset can be anywhere from 30 minutes (fromStaphylococcus aureus) to 4 weeks (fromListeria), andsymptoms can be similarfor the different infections.
If your symptoms are severe or last more than three days, your healthcare provider may order astool culturefor bacteria and viruses to see if they can identify the problem. If your test results are positive, your local health department may contact you to determine where you may have been infected.
Bloody diarrhea and fever are not typical signs of viral gastroenteritis, and those signs may indicate an infection with foodborne or waterborne bacteria or parasites, not with a virus.
How Long Is the Stomach Flu Contagious?
Excessive vomiting and diarrhea can lead to dehydration. Infants, children, older adults, and people with weakened immune systems are most at risk of becoming dehydrated from a stomach bug.
Dehydration can usually be prevented or managed, if treated properly. Severe dehydration is an emergency, as it can cause kidney issues (including failure), seizures, low blood volume, coma, and death.
Thesigns and symptoms of dehydrationinclude:
Children and adults who are dehydrated may have “skin-tenting,” in which the skin does not flatten back out immediately if you pinch it.
In babies and small children specifically, also watch for:
What to Do at the First Signs of Stomach Flu
At the first signs of stomach flu, you should assume that the cause is infectious andwork to preventthe spread of the stomach infection to others. Your stool and vomit may contain viruses for up to two weeks after you recover.
This means thorough handwashing with soap for at least 20 seconds:
People who are actively vomiting or have diarrhea should not go to work, daycare, or school. Babies who still use diapers should not use swimming pools for at least a week after diarrhea resolves.
Clean surfaces that may have come into contact with stool or vomit with a solution of 5 to 25 tablespoons of bleach per 1 gallon of water. Clean any potentially infected clothing or linen with the longest possible laundry cycle and machine dry them.
These Foods Can Help You Recover From the Flu Faster (and Some You Should Avoid)
If you have a fever greater than 101.3 F degrees (38.5 C) for more than 24 hours, cannot keep liquids down for more than 24 hours, or show signs of dehydration, call your healthcare provider. They can prescribe medications todecrease vomitingand may recommend treatment with intravenous (IV) fluids.
Seek immediate medical attention for the following symptoms:
In addition, children with the following symptoms should be seen immediately:
How long does the stomach flu last?
It depends on the virus causing the symptoms. The most common cause of viral gastroenteritis is norovirus, and most people have a resolution of norovirus symptoms in less than 48 hours.
What can I eat with the stomach flu?
How do I avoid getting the stomach flu if my family has it?
Make sure to wash your hands well with soap and water for at least 20 seconds before eating or putting your hands near your face. Don’t have infected people prepare your food. Clean your hands after touching common objects, and make sure to sanitize objects with bleach.
8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institutes of Health.Viral gastroenteritis.Bányai K, Estes MK, Martella V, Parashar UD.Viral gastroenteritis.Lancet. 2018;392(10142):175-186. doi:10.1016/S0140-6736(18)31128-0U.S. Centers for Disease Control and Prevention.Burden of foodborne illness: Findings.U.S. Centers for Disease Control and Prevention.Foodborne germs and illnesses.U.S. Centers for Disease Control and Prevention.Food poisoning symptoms.Hartman S, Brown E, Loomis E, Russell HA.Gastroenteritis in children.AFP. 2019;99(3):159-165.Fleisher GR, O’Ryan MG.Patient education: Acute diarrhea in children (Beyond the Basics).UpToDate.Patient education: Diarrhea in adolescents and adults (The Basics).Additional ReadingO’Shea H, Blacklaws BA, Collins PJ, McKillen J, Fitzgerald R.Viruses associated with foodborne infections.Reference Module in Life Sciences. Published online 2019. doi: 10.1016/B978-0-12-809633-8.90273-5Robilotti E, Deresinski S, Pinsky BA.Norovirus.Clin Microbiol Rev. 2015;28(1):134-164. doi: 10.1128/CMR.00075-14U.S. Centers for Disease Control and Prevention.Prevent the spread of norovirus.U.S. Centers for Disease Control and Prevention.Foodborne germs and illnesses.
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institutes of Health.Viral gastroenteritis.Bányai K, Estes MK, Martella V, Parashar UD.Viral gastroenteritis.Lancet. 2018;392(10142):175-186. doi:10.1016/S0140-6736(18)31128-0U.S. Centers for Disease Control and Prevention.Burden of foodborne illness: Findings.U.S. Centers for Disease Control and Prevention.Foodborne germs and illnesses.U.S. Centers for Disease Control and Prevention.Food poisoning symptoms.Hartman S, Brown E, Loomis E, Russell HA.Gastroenteritis in children.AFP. 2019;99(3):159-165.Fleisher GR, O’Ryan MG.Patient education: Acute diarrhea in children (Beyond the Basics).UpToDate.Patient education: Diarrhea in adolescents and adults (The Basics).Additional ReadingO’Shea H, Blacklaws BA, Collins PJ, McKillen J, Fitzgerald R.Viruses associated with foodborne infections.Reference Module in Life Sciences. Published online 2019. doi: 10.1016/B978-0-12-809633-8.90273-5Robilotti E, Deresinski S, Pinsky BA.Norovirus.Clin Microbiol Rev. 2015;28(1):134-164. doi: 10.1128/CMR.00075-14U.S. Centers for Disease Control and Prevention.Prevent the spread of norovirus.U.S. Centers for Disease Control and Prevention.Foodborne germs and illnesses.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Institutes of Health.Viral gastroenteritis.Bányai K, Estes MK, Martella V, Parashar UD.Viral gastroenteritis.Lancet. 2018;392(10142):175-186. doi:10.1016/S0140-6736(18)31128-0U.S. Centers for Disease Control and Prevention.Burden of foodborne illness: Findings.U.S. Centers for Disease Control and Prevention.Foodborne germs and illnesses.U.S. Centers for Disease Control and Prevention.Food poisoning symptoms.Hartman S, Brown E, Loomis E, Russell HA.Gastroenteritis in children.AFP. 2019;99(3):159-165.Fleisher GR, O’Ryan MG.Patient education: Acute diarrhea in children (Beyond the Basics).UpToDate.Patient education: Diarrhea in adolescents and adults (The Basics).
National Institutes of Health.Viral gastroenteritis.
Bányai K, Estes MK, Martella V, Parashar UD.Viral gastroenteritis.Lancet. 2018;392(10142):175-186. doi:10.1016/S0140-6736(18)31128-0
U.S. Centers for Disease Control and Prevention.Burden of foodborne illness: Findings.
U.S. Centers for Disease Control and Prevention.Foodborne germs and illnesses.
U.S. Centers for Disease Control and Prevention.Food poisoning symptoms.
Hartman S, Brown E, Loomis E, Russell HA.Gastroenteritis in children.AFP. 2019;99(3):159-165.
Fleisher GR, O’Ryan MG.Patient education: Acute diarrhea in children (Beyond the Basics).
UpToDate.Patient education: Diarrhea in adolescents and adults (The Basics).
O’Shea H, Blacklaws BA, Collins PJ, McKillen J, Fitzgerald R.Viruses associated with foodborne infections.Reference Module in Life Sciences. Published online 2019. doi: 10.1016/B978-0-12-809633-8.90273-5Robilotti E, Deresinski S, Pinsky BA.Norovirus.Clin Microbiol Rev. 2015;28(1):134-164. doi: 10.1128/CMR.00075-14U.S. Centers for Disease Control and Prevention.Prevent the spread of norovirus.U.S. Centers for Disease Control and Prevention.Foodborne germs and illnesses.
O’Shea H, Blacklaws BA, Collins PJ, McKillen J, Fitzgerald R.Viruses associated with foodborne infections.Reference Module in Life Sciences. Published online 2019. doi: 10.1016/B978-0-12-809633-8.90273-5
Robilotti E, Deresinski S, Pinsky BA.Norovirus.Clin Microbiol Rev. 2015;28(1):134-164. doi: 10.1128/CMR.00075-14
U.S. Centers for Disease Control and Prevention.Prevent the spread of norovirus.
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