- What Is
- How Do You Get It
- Recovery Time
What is the stomach flu (gastroenteritis)?
Stomach flu or gastroenteritis is a general term for a number of inflammatory problems that occur in the gastrointestinal tract. Gastroenteritis is a better term because when some individuals use the term "stomach flu," they get the term confused with the flu (influenza) and the viruses that cause the flu. Influenza viruses do not cause stomach flu.
The most common symptoms of the stomach flu include:
Other symptoms may include:
- Body aches
Because stomach flu means gastroenteritis and, because when the term “stomach flu” is used, the readers usually mean acute gastroenteritis caused by viruses (mainly Norovirus); the emphasis of this article will be on Norovirus-caused gastroenteritis although other causes will be mentioned.
Is the stomach flu contagious? What causes it?
There are many causes of stomach flu. The most common cause is contagious gastroenteritis which can be due to:
- Viruses (for example, Norovirus, Adenovirus and others)
- Bacteria (for example, Salmonella, Shigella, E. coli and others)
- Parasites (for example Giardia lamblia, Cryptosporidium, and others)
However, many other causes of gastroenteritis that are not contagious include:
- Food allergies
Many medications also list gastroenteritis as a common side effect.
What are the signs and symptoms of the stomach flu?
The primary symptoma of stomach flu or gastroenteritis include:
The incubation time for gastroenteritis varies according to the particular cause. The most rapid incubation time is usually with viral illnesses (for example, for Norovirus, which is about 1-2 days), and the infected person may become contagious during this time without symptoms of nausea or diarrhea.
Noncontagious causes (allergies, toxins, medication side effects) may produce symptoms very rapidly (minutes to hours) and in some people, the symptoms may become so severe that they require emergency care.
Doctors usually base the diagnosis on the person's history and physical exam; some patients will need further blood and fecal tests done to determine the cause, especially in more severe infections.
How is the stomach flu spread (how do you get it)?
Stomach flu typically spreads in the following ways:
- Contagious cases of stomach flu (gastroenteritis) are spread usually through contamination of food or water or by person-to-person (fecal-oral route) spread via contaminated droplets containing infectious organisms.
- Some contagious cases of gastroenteritis (most notably, Norovirus) can be spread by kissing and other close personal contact or on surfaces where droplets containing viruses or other agents survive.
- Some viruses can even be spread to household pets such as dogs that, in turn, can spread the disease to other people.
Fortunately, most causes of contagious gastroenteritis are not spread by breastfeeding or through breast milk. Noncontagious gastroenteritis such as that related to side effects of medicine or food allergies is not spread from person to person.
- Women's Gymnastics Brings High Risk for Concussion
- Going Solo: Masturbation May Give Humans an Evolutionary Edge
- Longer Breastfeeding in Infancy, Better School Grades for Kids?
- Kids With ADHD, Behavior Issues Have Poorer Trajectories as Adults
- FDA Finalizes Limit on How Much Arsenic Can Be in Apple Juice
- More Health News »
How long is the stomach flu contagious (incubation period)?
Stomach flu is contagious when the organisms that cause stomach flu are spread to uninfected individuals. The timeframe or how long the infected person remains contagious depends on the infecting cause. For example, most common cause of stomach flu is Norovirus. It has an incubation period of about 12-48 hours, and can cause the person to be contagious during the incubation period and for as long as they shed virus (usually about 3 days after symptoms stop but sometimes up to 2 weeks). Norovirus symptoms usually last about1-2 days and is sometimes called the 24-hour stomach flu.
Other infectious agents such as other viral strains, bacteria, and other infectious agents have incubation periods and contagious periods unique to them. Because this is an introductory article about stomach flu, readers are recommended to check the incubation periods and contagious periods of whatever infectious agent is thought to be causing the problem (for example, Salmonella or E. coli).
How long does the stomach flu last?
For contagious causes of stomach flu, many individuals have symptoms that last about 2 to 5 days, after which the symptoms tend to resolve. Once the symptoms resolve, an individual may be considered "cured" of stomach flu. However, it's not unusual for that same individual to develop stomach flu again at some point in time if they are exposed to other causes, or in some individuals, the same infectious cause. Occasionally, the stomach flu "symptoms" progress and goes on to become another more severe disease (for example, salmonellosis or shigellosis).
How long do the contagious causes of the stomach flu last on surfaces?
The most common cause of stomach flu, noroviruses, can live on surfaces for up to about 2 weeks. Therefore, is important to try to avoid contaminating surfaces while you are infected with the virus. Equally important, anyone not infected individual should wash their hands with soap and water after touching surfaces that might be contaminated. Cleaning surfaces like doorknobs or kitchen counters with a diluted bleach and water solution can help reduce the chance of infection.
For other causes of stomach flu (gastroenteritis), the reader is suggested to look up the specific infectious agent to determine how long it will remain viable and contagious on surfaces.
When should I contact a doctor for the stomach flu?
Many people get contagious stomach flu from different causes, but in general, they recover from the infection in about 2 to 5 days and usually do not contact a health care professional. Most doctors consider gastroenteritis to be a self-limiting disease. Unfortunately some people, especially the elderly, young children, and individuals that have multiple medical problems may develop more severe symptoms. Consequently, people should contact their health care professional or emergency department if one or more in the following cases:
- Gastroenteritis symptoms that last more than 5 days
- Worsened intensity of symptoms
- Fever above 101 F or 38.3 C
- Bloody diarrhea
- Signs of dehydration such as little or no urine output or dry mucous membranes
- Constant or increasing abdominal pains
- Person is immunocompromised, has other medical problems, or is pregnant
- Facial or throat swelling
- Shortness of breath
Subscribe to MedicineNet's General Health Newsletter
Health Solutions From Our Sponsors
CDC. Norovirus. Oct 05, 2018.
Diskin, A, MD, et al. "Emergent Treatment of Gastroenteritis." Medscape. Updated: Feb 10, 2017.
Top Is the Stomach Flu (Gastroenteritis) Contagious Related Articles
Food PoisoningConcerned about food poisoning outbreaks? From ground beef to lettuce, many foods can cause them. Learn about foodborne diseases like Salmonella, E. coli, norovirus, Campylobacter, Staph, and hepatitis A.
Abdominal PainAbdominal pain can have many causes that range from mild to severe. Some of these causes include bloating, gas, colitis, endometriosis, food poisoning, GERD, IBS (irritable bowel syndrome), ovarian cysts, abdominal adhesions, diverticulitis, Crohn's disease, ulcerative colitis, gallbladder disease, liver disease, and cancers. Signs and symptoms of the more serious causes include dehydration, bloody or black tarry stools, severe abdominal pain, pain with no urination or painful urination. Treatment for abdominal pain depends upon the cause.
Can Gastroenteritis Cause a High White Blood Cell Count?What is gastroenteritis, and does it cause a high white blood cell count? Learn the symptoms and causes of gastroenteritis.
Digestive Disorders: Worst Foods for DigestionDiscover which foods to avoid in order to prevent diarrhea and digestive problems. Find out which foods can trigger diarrhea and other digestive problems such as gas, bloating, indigestion, heartburn and more.
Food PoisoningFood poisoning is common but can also be life-threatening. Food poisoning symptoms include stomach cramps, diarrhea, and vomiting. Read about different types of food poisoning, treatment, and tips for prevention.
Stomach Flu (Gastroenteritis)Stomach flu (gastroenteritis) is a term referred used to describe a variety of gastrointestinal problems. The most common signs and symptoms of gastroenteritis are nausea, vomiting, diarrhea, and abdominal pain. The most common cause of gastroenteritis in the United States is Norovirus. Other causes of gastroenteritis include Rotavirus, Astrovirus, Adenovirus, and Sapovirus. There are bacterial causes of gastroenteritis such as Salmonella, Shigella, Campylobacter Aeromonas, E. coli, Clostridium, Vibrio, Campylobacter, and Yersinia spp. Parasites that cause gastroenteritis include Giardia, Cryptosporidium, Cyclospora, and Entamoeba. Treatment for gastroenteritis is generally home remedies such as keeping hydrated to prevent dehydration. At times, hospitalization may be necessary if dehydration occurs.
How Do You Relieve Upper Stomach Pain?What causes upper stomach pain? Learn what can cause upper stomach pain and what remedies can help relieve symptoms.
IBS-D (Irritable Bowel Syndrome with Diarrhea)
IBS-D or irritable bowel syndrome with diarrhea refers to IBS with diarrhea. Symptoms of IBS-D include
- intestinal gas (flatulence),
- loose stools,
- frequent stools,
- abdominal pain,
- diarrhea, and
New non-FDA approved IBS tests may help diagnose IBS and IBS-D. Treatment of IBS-D is geared to toward managing symptoms with diet, medication, and lifestyle changes.
Nausea and VomitingNausea and vomiting are symptoms of many conditions including motion sickness, pregnancy, emotional stress, gallbladder disease, and other illnesses. Learn about causes, treatment, and when to be concerned.
How to Get Rid of Nausea and VomitingWhat is nausea? Do you want to know how to get rid of nausea and how to stop vomiting? Learn home remedies for nausea, anti-nausea medication, what causes nausea, and other info crucial to nausea relief. Understand why we vomit, how vomiting can be treated or prevented, and more.
Norovirus InfectionNorovirus infection causes stomach flu, or gastroenteritis. It's a very contagious illness with symptoms that include nausea and vomiting, diarrhea, stomach cramps, fever, headache, chills, and muscle aches. Norovirus infection cannot be treated with antibiotics, so treatment focuses on maintaining proper hydration.
Salmonella Food PoisoningSalmonella infection (salmonellosis) is typically caused by the consumption of contaminated foods. Symptoms of salmonellosis include fever, vomiting, diarrhea, and abdominal pain. Salmonellosis typically resolves on its own in four to seven days. It's important to increase one's fluid intake to compensate for the fluid lost by vomiting and/or diarrhea.
Stomach Flu vs. Food Poisoning
The stomach flu (viral gastroenteritis) and food poisoning are not the same infections. However, they do have a few similar symptoms, for example:
- Abdominal (stomach) pain and cramping.
Symptoms and signs of food poisoning show up earlier (2 hours up to a couple of days) in comparison to the stomach flu in which symptoms may take 4 hours up to 48 hours (2 days) before symptoms begin. Medical treatment for the stomach flu and food poisoning generally is not necessary. A bland diet, drinking plenty of fluids, and rest may be the only treatment necessary.
Stomach PictureThe stomach is a muscular sac located on the left side of the upper abdomen. See a picture of the Stomach and learn more about the health topic.
Tummy Trouble QuizTummy Troubles? Get a better idea of what's causing the nausea, vomiting, bloating, gas, constipation, diarrhea, pain, and other gastrointestinal discomforts and problems. Take the Tummy Troubles Quiz!
What's a Virus?Is a virus alive? Learn the definition of a virus. Viral infections like COVID-19 can occur in your eyes, mouth, skin, or anywhere else. Should you use antibiotics to treat the flu? Is this STD a bacterium or a virus? Get the answers to the most common questions about viral infections.