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Food poisoning on holiday: what to do first

The first few hours, what actually helps, and the symptoms that mean it is time to involve a doctor.

Pomodoc editorial teamUpdated 10 min read

Medically reviewed by Dr. Diogo Figueiredo Gonçalves, MD, Specialist Physician in Family Medicine —

General information, not a diagnosis. If you are worried about your symptoms, speak with a doctor.

A woman at an outdoor taverna table with both hands pressed to her stomach and her eyes closed, a barely touched plate of food in front of her and a chalkboard of the day's specials behind.

The short answer

For most healthy adults, food poisoning is managed by rest and by replacing fluids, and it settles on its own. NHS guidance says food poisoning is rarely serious and usually gets better within a week, with diarrhoea normally stopping within five to seven days and vomiting within one or two. Sip fluids steadily, eat when you feel able to, and skip anything fatty or spicy. Get medical help sooner if there is blood in your stool, if you cannot keep any fluids down, if symptoms last beyond those windows, or if the person affected is a baby, a young child, pregnant, older, or has a condition that makes dehydration riskier.

Worth knowing

  • Dehydration, not the infection itself, is the main thing that turns a bad day into a medical problem. The World Health Organization describes it as the most severe threat posed by diarrhoea.
  • NHS guidance: diarrhoea usually stops within five to seven days, vomiting within one or two.
  • Oral rehydration sachets are worth using rather than guessing, particularly for older travellers, anyone immunocompromised, and anyone with a condition that raises dehydration risk.
  • Blood in your stool, vomiting that will not stop, and severe abdominal pain are not part of a normal stomach bug. They are reasons to get help.
  • NHS guidance is that anti-diarrhoeal medicine should not be given to children under 12.
In this guide

What should you do in the first few hours?

Nothing clever. The goal for the first few hours is to lose less fluid than you take in, and to give yourself somewhere comfortable to be while your body deals with it.

  1. Stop the dayCancel whatever you had planned and stay near a bathroom. Pushing through a stomach bug on a coach tour or a boat trip goes badly and slowly.
  2. Start sipping, not gulpingNHS advice is to drink lots of fluids such as water, and to take small sips if you feel sick. Small and frequent stays down when a full glass will not.
  3. Get oral rehydration sachetsA pharmacy will have them. They are rehydration powder you mix with clean water, and they replace salts as well as water, which plain water does not. The WHO describes oral rehydration solution simply as a mixture of clean water, salt and sugar.
  4. Eat when you can face itThere is no need to starve yourself. NHS guidance is to eat when you feel able to, and that it may help to avoid foods that are fatty or spicy. Skip fruit juice and fizzy drinks while symptoms are active.
  5. Note what changedWhen symptoms started, what you ate or drank that was out of the ordinary, and whether things are improving or not. If you do end up speaking to a doctor, this is most of what they will ask.

How long does food poisoning usually last?

NHS guidance is that symptoms usually start within a few hours or a few days of eating the food responsible, though sometimes they do not start for a few weeks. Food poisoning is described as rarely serious and usually getting better within a week.

Separately, NHS guidance on diarrhoea and vomiting gives clearer windows to measure yourself against: diarrhoea usually stops within five to seven days, and vomiting usually stops in one or two. Those numbers are useful precisely because they give you a point at which waiting is no longer the plan.

How do you stay hydrated when you cannot keep much down?

This is the part that matters most, and the part people get wrong by drinking a lot occasionally instead of a little constantly.

The WHO defines diarrhoea as passing three or more loose or liquid stools a day, or more often than is normal for you, and identifies dehydration as the most severe threat it poses. Signs of severe dehydration it lists include being lethargic or unconscious, sunken eyes, being unable to drink, and a skin pinch that goes back very slowly, taking two seconds or more.

NHS guidance is that a pharmacist may recommend oral rehydration powder mixed with water if you have signs of dehydration, if you are an older person, if you are immunocompromised, or if you have another condition that raises your dehydration risk. If you are travelling with anyone in those groups, buying sachets before you need them is a small, sensible bit of luggage.

For babies, NHS guidance is to keep going with breast or bottle feeding, offering small sips of water between feeds for formula-fed babies, and not to weaken the formula.

Where you are changes the practical detail more than the medicine: whether the tap water is safe for mixing sachets, what a pharmacy will stock, and who to call. Our destination guides cover that for a stomach upset at a Dominican Republic resort and for food poisoning in Egypt.

Which symptoms mean you should stop treating it yourself?

The list below is NHS guidance for when to get medical help rather than wait it out. It is worth reading properly rather than skimming, because several of these are easy to talk yourself out of.

One more worth naming explicitly, because travellers routinely wait on it: tummy pain that is getting severe. A sudden, severe tummy ache is on the NHS emergency list below, not the wait-and-see one. And if you are not sure whether what you have is still a routine upset, that uncertainty is itself a reason to speak to a doctor rather than give it another day.

When is it an emergency?

Anywhere in the EU, 112 reaches an ambulance free of charge from a fixed line or a mobile. Elsewhere, look up the local number now rather than later.

For everything short of an emergency, the warning signs, the thresholds and when a video consultation is a sensible first step are set out on our page about seeing an online doctor for food poisoning.

What about anti-diarrhoeal medicine and antibiotics?

Two different questions, and the honest answer to both is that they depend on your situation more than most travel advice admits.

Anti-diarrhoeal medicine

NHS guidance is that a pharmacist may recommend medicine to stop diarrhoea for a short time, that it is not suitable for children under 12, and that you should not give children under 12 medicine to stop diarrhoea. It is worth knowing that slowing things down is not the same as treating the cause, and that it is not the right move in every case. A pharmacist or a doctor can tell you whether it fits your situation. This article deliberately does not tell you which product or how much, because that depends on you.

Antibiotics

Whether antibiotics are appropriate is a clinical decision, not a traveller's decision. Most cases do not need them. Taking antibiotics you happen to have with you, or buying them over a counter because a stomach bug feels serious, is a poor idea on two counts: they will not help most causes, and unnecessary use contributes to antibiotic resistance. If your symptoms are severe or not improving, that is the conversation to have with a doctor, who can weigh it properly.

One more from NHS guidance that catches people out: do not give aspirin to children under 16. If it is a child who is unwell, our guide to handling illness when travelling with kids covers fever, dehydration signs and when a child needs to be seen.

Who needs to be more careful?

NHS guidance identifies higher-risk groups for food poisoning: babies under 12 months, children under five, older people, anyone with a weakened immune system, and anyone with other health conditions. Pregnancy is also a reason to get advice earlier rather than later rather than manage it alone.

If any of that describes you or the person you are travelling with, treat the thresholds above as lower. Do not wait for the seven-day mark to become relevant. Getting an assessment early costs you twenty minutes; getting it late can cost you the rest of the trip.

When can you get back to your trip?

When you can hold down fluids, eat something ordinary, and be more than a few minutes from a bathroom without calculating. Ease back in rather than making up for lost time on day one. Rich food and a long day out are the two most reliable ways to restart the whole thing.

If you also need to replace medication you have run out of or lost while unwell, our guide to prescriptions abroad covers what actually works. And if you have decided you do want to be seen, the five ways to see a doctor abroad compares them honestly, including when a video call is the wrong choice.

A stomach upset is one of several travel complaints that a video doctor can usually assess without seeing you in person. The others, from rashes to infected insect bites, are in five common travel illnesses a video doctor can help with.

Common questions

How do I know if it is food poisoning or a stomach virus?

From symptoms alone, often you cannot, and for the first day it usually does not change what you do: rest and replace fluids either way. The distinction starts to matter if symptoms are severe, if there is blood in your stool, or if they last past the windows above, which is the point at which a doctor should be looking at it rather than an article.

Should I take the anti-diarrhoeal tablets I packed?

Ask a pharmacist or a doctor rather than deciding from a list of symptoms. NHS guidance is that these medicines are not suitable for children under 12 and should not be given to them. For adults they can help for a short period in some situations and are the wrong choice in others, which is why this article does not name a product or a dose.

Can I drink the tap water to rehydrate?

Only where tap water is safe to drink, which is not everywhere. Where it is not, use sealed bottled water for drinking and for mixing rehydration sachets, and skip ice. WHO prevention guidance for diarrhoeal disease centres on access to safe drinking water, sanitation and handwashing with soap.

My child has it. Is the advice the same?

No, the thresholds are lower and some of the advice is different. NHS guidance says to get help if you are worried about a baby under 12 months, if a child stops feeding while unwell, or if a child under five shows signs of dehydration such as fewer wet nappies, and it says not to give children under 12 medicine to stop diarrhoea or aspirin to children under 16. If a child is affected, get advice earlier than you would for yourself.

Is it worth seeing a doctor for a stomach bug at all?

For a mild case that is improving, usually not. It is worth it when you are not sure whether what you have is still routine, when you are in a higher-risk group, when symptoms have gone past the usual windows, or when you need someone to tell you whether to keep managing it or go and be seen. That last one is the most common reason travellers get in touch, and it is a reasonable one.

Can I fly with food poisoning?

The NHS food poisoning pages do not give a rule on flying. In practice, a flight while you are still vomiting or losing a lot of fluid is miserable and makes keeping fluids up harder. If you have a flight you cannot move and you are still unwell, get medical advice before you travel rather than at the gate.

Sources

  1. Food poisoningNHSSymptoms and onset, that food poisoning is rarely serious and usually gets better within a week, the self-care advice, the higher-risk groups, and the guidance not to give anti-diarrhoeal medicine to children under 12 or aspirin to children under 16.
  2. Diarrhoea and vomitingNHSThat diarrhoea usually stops within five to seven days and vomiting within one or two, who oral rehydration powder is recommended for, and the full lists of symptoms needing urgent or emergency help.
  3. Diarrhoeal diseaseWorld Health OrganizationThe definition of diarrhoea as three or more loose or liquid stools a day, that dehydration is the most severe threat it poses, the signs of severe dehydration, what oral rehydration solution is, and the prevention measures.
  4. 112, the European emergency numberEuropean CommissionThat 112 reaches an ambulance free of charge from a fixed line or a mobile anywhere in the EU.