With norovirus, you can vomit many times a day, often suddenly and violently, with vomiting typically lasting 1 to 2 days, though diarrhea can persist longer, leading to a high risk of dehydration, especially for the very young and elderly.
Diarrhea, stomach pain and vomiting typically begin 12 to 48 hours after exposure. Norovirus infection symptoms usually last 1 to 3 days. Most people recover completely without treatment.
For many people, stomach flu symptoms seem to come on suddenly and out of nowhere. You might throw up or have diarrhea many times on that first day. Symptoms occur one to two days after you were exposed to the virus. Fortunately, they're usually over just as quickly, resolving in one to two days.
A person with norovirus can feel very sick and may vomit or have diarrhea many times a day. This can cause dehydration, especially in young children, older adults, and people with health conditions that weaken the immune system.
Speak to your GP if: you've been vomiting repeatedly for more than a day or two. you're unable to keep down any fluids because you're vomiting repeatedly. you have signs of severe dehydration, such as confusion, a rapid heartbeat, sunken eyes and passing little or no urine.
Make an appointment with your doctor if: Vomiting lasts more than two days for adults, 24 hours for children under age 2 or 12 hours for infants. You've had bouts of nausea and vomiting for longer than one month. You've experienced unexplained weight loss along with nausea and vomiting.
How to treat norovirus yourself
Norovirus infection is usually diagnosed based on your symptoms, but noroviruses can be identified from a stool sample. If you have a weakened immune system or have other medical conditions, your health care provider might recommend a stool test to confirm the presence of norovirus.
Other viral agents that cause human acute infectious gastroenteritis that is difficult to distinguish from disease caused by rotaviruses and noroviruses include the sapovirus (like norovirus, a member of the Caliciviridae family), enteric adenoviruses (Chapter 373) belonging to types 40 and 41, and astroviruses (Table ...
In most cases, gastro starts with vomiting and then leads to diarrhoea (runny, watery poo). The vomiting may settle quickly, but the diarrhoea can last up to 10 days. Many germs can cause gastro, but a virus is the most common. Gastro spreads easily and is more common and severe in babies and young children.
What causes acute vomiting?
The uptick in norovirus started slightly earlier than usual and appears to be driven by a newer variant of the virus, which fueled a harsh 2024-2025 season. Last winter, norovirus outbreaks surged to decade-high levels.
Each year in the US, norovirus causes: 19-21 million cases of vomiting and diarrhea. Approximately 109,000 hospitalizations. Nearly 2.3 million outpatient visits.
The green colour of poo, if someone has a gut infection, is usually caused by the bacteria salmonella, a parasite called giardia, or a virus called norovirus. Most gut infections do improve in five to ten days with self-care. Read more about food poisoning and gut infections here.
How the Emergency Room Handles Norovirus. If you do end up needing ER care, here's what to expect: IV Fluids: For those severely dehydrated, intravenous fluids are the fastest way to replenish the body. Medication for Symptoms: Antiemetics can help stop vomiting, while other medications may ease severe cramping.
The first symptom is usually a sudden onset of feeling sick, which is followed by violent vomiting and watery diarrhoea. Vomiting is the most common symptom, but you may have diarrhoea without vomiting or vomiting without diarrhoea.
Most people with norovirus illness have both diarrhea and vomiting. How long does the illness last? The illness is usually brief, with symptoms lasting only about 1 or 2 days.
Avoid lying down right away, as this can cause discomfort. Instead, stay seated after eating to support digestion and reduce the risk of vomiting. Once you're able to eat, start with small amounts of bland food, eat slowly, and give your stomach time to digest.
Norovirus can make it difficult for you to eat or drink because the inflammation in your intestines and stomach causes you to vomit or have diarrhea.
While occasional vomiting is usually not cause for immediate concern, certain situations warrant prompt medical attention. It's important to seek help if you notice blood in your vomit, or if the vomit appears very dark or black.
Get emergency care if nausea or vomiting is accompanied by:
Coughing and vomiting white foam could be linked to acute asthma or accidental ingestion of substances like hydrogen peroxide.
If someone has the following symptoms, they should stay home because their illness could affect their ability to participate in school and there is concern that they might spread an infection to staff and students. Fever, including a fever with a new rash. Vomiting more than twice in the preceding 24 hours.
First-line therapy in the emergency department is the use of metoclopramide, but dom- peridone, erythromycin, and antiemetics are also often used, and interventional therapy should be reserved for refractory cases.