Norovirus symptoms. What to eat and drink to recover

A single norovirus particle has about a 50% chance of infecting you. That estimate comes from a 2008 study of human volunteers, and it is higher than for any other virus the authors had seen studied. It explains why one sick guest can bring down a whole family, a cruise ship or a care home in days.

Norovirus symptoms come on fast and feel awful, but most people get better within 1 to 3 days. In this guide I explain the symptoms, how long they last and what to eat and drink to recover. I also cover what the bug can do to your gut afterwards, because that part rarely gets talked about.

What are the symptoms of norovirus?

The main norovirus symptoms are diarrhoea, vomiting, nausea and stomach pain. The US Centers for Disease Control and Prevention (CDC) lists these as the most common ones. Some people also get a fever, a headache and body aches.

The NHS in the UK calls norovirus the winter vomiting bug. It says symptoms usually start suddenly. You can feel fine at lunch and be rushing to the bathroom by evening.

• Nausea and vomiting, often the first and most dramatic sign.
• Watery diarrhoea, which usually lasts a little longer than the vomiting.
• Stomach cramps and pain, often around the belly button.
• Fever, headache and aching muscles in some people.

In a 2009 drinking water outbreak at Lake Garda in Italy, 348 people who got sick filled in a survey. Diarrhoea lasting 2 to 3 days or more was reported by 77%, and 60% had vomiting. Half had a fever. About 1 in 5 lost weight, 3 kg (about 6.6 lb) on average.

How soon do norovirus symptoms start?

Symptoms usually start 12 to 48 hours after you are exposed to the virus, according to the CDC. So if you feel sick today, think back over the last 2 days. A shared meal, a sick child or a crowded event are the usual sources.

The virus spreads through tiny amounts of poo or vomit. You can catch it from close contact with a sick person or from touching a surface with the virus on it and then your mouth. Food or water handled by someone who is sick can spread it too, and so can shellfish such as oysters.

How long does norovirus last?

Most people feel better within 1 to 3 days, the CDC says. The NHS gives the same picture, with most people better in about 2 days. In general, NHS advice says vomiting usually stops in 1 or 2 days and diarrhoea within 5 to 7 days.

Some people take longer. A Dutch community study published in 2002 followed 99 people with norovirus. Their symptoms lasted a median of 5 days. So do not panic if you are still a bit loose on day 4 or 5. What matters is that you drink well and improve each day.

How long are you contagious?

You can still spread the virus after you feel better. The CDC says the virus can stay in your poo for 2 weeks or more. In a 2014 volunteer study, people shed the virus in their stools for up to 3 weeks after their symptoms ended.

The NHS advises staying off work or school until you have had no vomiting or diarrhoea for 2 days. The CDC says to wait at least 48 hours after symptoms stop before you prepare food for others. I would keep washing your hands very well for a couple of weeks after that.

How common is norovirus?

Norovirus is one of the most common causes of stomach bugs in the world. A 2014 review in The Lancet Infectious Diseases pooled data from 187,336 people with gastroenteritis. Norovirus was found in 18% of them, almost 1 in 5.

In the US alone, the CDC estimates 19 to 21 million illnesses a year. Outbreaks happen all year, but they are most common from November to April. A 2016 study put the global cost at about 60 billion US dollars a year, mostly from lost work and school days.

Why do some people never seem to catch it?

Your genes may play a part. In a 2003 challenge study in Nature Medicine, 29% of volunteers lacked a working copy of a gene called FUT2. Without it, the original Norwalk strain of norovirus has nowhere to attach in the gut. None of these people got infected, whatever dose they were given.

This protection does not cover every strain, so nobody should think they are immune. But I find it a striking reminder that what happens in your gut depends partly on what is written in your DNA.

What should you drink with norovirus?

Fluids matter far more than food in the first day or two. Diarrhoea and vomiting drain water and salts from your body fast. Dehydration is the main danger, especially for babies, young children, older adults and anyone with other health problems.

1. Take small, frequent sips. A few sips every 5 to 10 minutes stay down better than a big glass. The NHS advises small sips if you feel sick.
2. Use an oral rehydration solution. The CDC says over-the-counter oral rehydration fluids are the most helpful choice for mild dehydration. They have the right balance of salt and sugar.
3. Water is fine for mild cases. The CDC says sports drinks and other drinks without caffeine or alcohol can help with mild dehydration. They may not replace all the minerals you lose.
4. Skip fruit juice and fizzy drinks. The NHS says they can make diarrhoea worse.
5. Keep feeding babies. Carry on with breast or bottle feeds, and do not make formula weaker than usual.

Check your pee. Pale yellow means you are keeping up. Dark, strong pee or peeing much less than usual are signs of dehydration. A dry mouth or dizziness when you stand up are signs too.

What should you eat when you have norovirus?

Eat when you feel able to, and start small. The NHS advises this and says it may help to avoid fatty or spicy foods. You do not need to starve yourself, and you do not need a special diet.

When I had IBS with diarrhoea, I learned how much gentle, simple food helps a sore gut settle. These are the foods I suggest in the first few days back.

Try this, day by day

• While vomiting. Fluids only, in small sips. Ice chips or an ice lolly can help if sips keep coming back up.
• First solid foods. Plain toast, crackers, white rice, plain pasta, boiled or mashed potato, porridge made with water and a ripe banana.
• Add protein. Clear soup or broth, scrambled or boiled eggs, plain chicken or fish and firm tofu.
• Back to normal. Cooked carrots and courgette (zucchini), yogurt or kefir if dairy sits well, then your usual fruit, vegetables and whole grains over a few days.

Go slowly with fried food, rich sauces, alcohol, strong coffee and very sugary drinks for a few days. Some people find milk harder to digest for a short while after a stomach bug. If milk upsets you, try lactose-free milk for a week or two. My guide to lactose and IBS explains why.

Is the BRAT diet still the best choice?

Bananas, rice, applesauce and toast are gentle foods, but you do not need to eat only those. The NHS simply says to eat when you can and go easy on fatty or spicy food. Staying on a very limited diet for days gives your body little protein. I prefer a short gentle start, then a fairly quick return to normal meals.

Do probiotics help with norovirus?

The best trials so far say probiotics do not help much with a stomach bug, at least in young children in rich countries. Two large trials were published together in the New England Journal of Medicine in 2018.

In the US trial, 971 children aged 3 months to 4 years got either Lactobacillus rhamnosus GG or a placebo for 5 days. The probiotic did not shorten diarrhoea or reduce severe illness. In the Canadian trial, 886 young children got a 2-strain probiotic or a placebo. Again, the probiotic made no clear difference.

These trials included many causes of gastroenteritis, not only norovirus, and they did not study adults. Still, I would not spend money on a probiotic to treat norovirus. My guide to probiotics for IBS covers where probiotics have better evidence.

Antibiotics do not help either. The CDC says they fight bacteria, not viruses, and there is no specific medicine for norovirus. Ask a pharmacist before taking anti-diarrhoea medicine, and the NHS says not to give it to children under 12.

Can norovirus cause IBS?

Yes, for some people a stomach bug is the start of IBS. This is called post-infection IBS, and it is a big part of why I believe the gut deserves care after any infection.

In the Lake Garda outbreak, researchers checked people again after 12 months. Among the people who had been sick, 40 had new IBS at 12 months. Only 3 people in a group from the same area who had not been sick had it. The authors put the rate at about 13%, similar to rates seen after bacterial food poisoning.

A 2017 review in Gastroenterology pooled 45 studies with 21,421 people who had a gut infection. About 10% had IBS a year later. The risk was higher in women, in people who took antibiotics during the illness and in people with anxiety or depression. A 2019 review noted there are still few good studies on viruses such as norovirus, so the norovirus figure rests mostly on that one outbreak.

I strongly believe the weeks after a stomach bug are a good time to be kind to your gut. Gentle meals, plenty of fluids, good sleep and less stress all help your gut lining and bacteria recover. If your gut still is not right after a few months, my guide to whether IBS can be cured explains what helps.

How do you stop norovirus spreading?

Soap and water beat hand gel against this virus. The CDC says hand sanitizer does not work well against it, and the NHS says alcohol hand gels do not kill it. Wash your hands with soap and water for at least 20 seconds, especially after the toilet and before you touch food.

A 2022 lab study tested 8 hand sanitizers on the fingertips of volunteers. None removed all of the virus. The best one, with 85% ethanol, did better than most, but formulas varied a lot.

• Clean with bleach. The CDC advises a chlorine bleach solution of 5 to 25 tablespoons of household bleach per US gallon of water (about 3.8 litres). Leave it on the surface for at least 5 minutes.
• Wash soiled laundry hot. Handle it with gloves, do not shake it, and wash it on the longest hot cycle. The NHS suggests a 60°C (140°F) wash.
• Do not cook for others while you are sick and for at least 2 days after symptoms stop.
• Do not share towels, cups or cutlery while anyone in the house is sick.

Holiday gatherings are a classic place for stomach bugs to spread. If you are hosting, my low FODMAP Thanksgiving plan has tips for a calm holiday meal. My travelling with IBS guide also covers food and water safety away from home.

When should you see a doctor?

Most people can look after themselves at home, but some warning signs need a doctor quickly. Get help if you cannot keep any fluids down or you have signs of dehydration that do not improve with oral rehydration drinks. Blood in your diarrhoea, vomit that looks like coffee grounds or a sudden, severe tummy ache also need urgent care.

The NHS also advises getting help for diarrhoea that lasts more than 7 days or vomiting that lasts more than 2 days. Babies under 12 months, older adults and people with weak immune systems need a lower threshold. The doctor box on this page lists every warning sign.

Not sure if your symptoms are normal? My quick Gut Check game can help you think it through, though it never replaces a doctor.

Frequently asked questions

What are the first signs of norovirus?

Norovirus often starts suddenly with nausea and vomiting, followed by watery diarrhoea and stomach cramps. Some people also have a mild fever, a headache or aching muscles. Symptoms usually appear 12 to 48 hours after you are exposed to the virus.

How long does norovirus last in adults?

Most adults feel better within 1 to 3 days, according to the CDC. Diarrhoea can hang on a little longer than vomiting, and one community study found a median of 5 days. You can still spread the virus for 2 weeks or more after you feel better, so keep washing your hands well.

What is the fastest way to recover from norovirus?

There is no medicine that cures norovirus, so rest and fluids are the key. Sip an oral rehydration solution or water often, and eat small plain meals when you feel ready. Avoid fruit juice, fizzy drinks, alcohol and fatty food for a few days.

Does hand sanitizer kill norovirus?

Not well. The CDC says hand sanitizer does not work well against norovirus, and the NHS says alcohol gels do not kill it. Washing with soap and water for at least 20 seconds is the best way to remove it from your hands.

Can you get norovirus twice?

Yes. The CDC says you can get norovirus many times in your life because there are many different types. Being infected with one type may not protect you against another, and nobody knows exactly how long protection lasts.

What I want you to remember

Norovirus symptoms hit hard and fast, but most people recover in 1 to 3 days. Your main job is to stay hydrated with small sips, ideally of an oral rehydration solution. Then return to gentle food and your normal meals over a few days.

Wash with soap and water, not just hand gel, and stay away from cooking for others for 2 days after you feel better. If your gut still feels unsettled months later, do not ignore it. My free 30-Day Calm Gut Challenge is a gentle place to start rebuilding.