Think you have food poisoning? Here’s what to do if you eat something that’s contaminated.
Medically reviewed by Dr Juliet McGrattan (MBChB) and words by Anna Bonet
Food poisoning can come after eating contaminated foodstuffs, re-heating leftovers or eating out-of-date food. It’s a common medical condition and whilst it usually clears up quickly, it can make you feel really unwell and afraid of going far from the toilet.
But how do you distinguish food poisoning from a simple stomach bug? And how can you prevent food poisoning in the first place? Kajsa Ernestam, health expert and in-house dietician at Lifesum, looks at the causes, treatments and best foods to eat if you get struck down by food poisoning.
Food poisoning symptoms
The symptoms of food poisoning can begin just a few hours after eating the contaminated food but there can be a gap of a few days or even weeks, making it harder to identify the cause.
According to Ernestam, the main symptoms include:
You may experience any combination of these symptoms. Vomiting often starts first followed by diarrhoea. The diarrhoea can be watery, explosive and very frequent. It may contain mucous and occasionally blood.
Pregnant women, young children, elderly people and those with underlying medical conditions or weak immune systems may be more severely affected and should contact their doctor if they have food poisoning.
What causes food poisoning?
Food poisoning occurs when you consume contaminated foodstuffs. ‘Food poisoning is the result of eating or drinking something that is either toxic, or that has been contaminated with germs, often by having been left out of the fridge for too long, not cooked properly, or eaten after its use by date,’ explains Ernestam. Food poisoning can also occur if the person preparing and handling the food has dirty hands or is unwell themselves.
Food can become contaminated at any point in its preparation. Common causes of food poisoning include:
- Not cooking meat thoroughly.
- Not reheating foods previously cooked foods.
- Leaving food out in warm temperatures.
- Leaving next to other foods which are contaminated.
- Not washing hands properly before preparing food.
Any food can give you food poisoning but common culprits include:
- Chicken and other raw poultry and meat
- Milk that is unpasteurised
- Raw eggs
- Pre-packed sandwiches
- Sandwich fillers such as pâté, cream cheese and sliced meat
Is it food poisoning or a stomach bug?
In many cases, food poisoning and gastroenteritis can be used interchangeably. And unfortunately, it’s difficult to tell clinically whether your symptoms are from eating contaminated food or because someone’s passed on a nasty bug to you.
Though it’s worth noting that diarrhoea illnesses are often caused by viruses rather than bacteria and are usually what we call “self limiting”, in other words, they can be managed at home without the need to see a doctor.
How to test for food poisoning
The only real way of knowing which bug is to blame is to send a sample to the laboratory for assessment and, as most cases of diarrhoea and vomiting settle within a couple of days, we don’t always do this.
How to treat food poisoning
While it is an uncomfortable experience, food poisoning is rarely serious and usually gets better within a week. However, in more severe cases, symptoms can linger for up to one month.
‘If you, or your child, has food poisoning then it is advised to stay home from school or work and to make sure that you rest and stay hydrated,’ says Ernestam. ‘Ensure that you wash your hands and do not prepare food, to avoid spreading it to anyone else.’
‘I recommend healing your body with nutrition and vitamins from natural foods, a lot of liquids, rest, and, when you are up for it, some fresh air,’ Ernestam adds.
Here are some treatment tips if you think you have food poisoning:
You lose fluids from your body through sweat, vomiting and diarrhoea. Drink plenty of fluids and sip small amounts frequently if you find them hard to keep down. Water is fine, you can use an Oral Rehydration Solution (available from pharmacies) if you are at high risk of dehydration. Avoid fizzy drinks, alcohol and caffeine.
Eat a bland diet
When you feel up to having some solid food, stick with simple, plain foods such as toast, rice, bananas and apples. Try small amounts at first and gradually build up as you feel better. Avoid spicy, rich and fatty foods.
Take time off
Stay off work or school until at least 48 hours after the last episode of diarrhoea to help prevent the spread of infection.
Food poisoning can leave you feeling exhausted, light headed and weak so rest as much as possible.
If you are vomiting a lot, then see your doctor who may give you an anti-emetic medicine, such as domperidone to help control this. You can also try using Enterosgel, which works by adsorbing the bacteria or toxins in the gut that cause diarrhoea. Enterosgel is suitable for children an
Best foods and drinks if you have food poisoning
If you’ve experienced a particularly nasty bout of food poisoning, you might feel like you never want to eat again, but it is important to keep yourself hydrated and sustained. The best food and drinks, according to Ernestam, include the following:
Applesauce is a great way to settle your stomach. Containing less fibre than apples (try to minimise your fibre intake when you’re suffering from food poisoning) the sauce is easy to digest and contains pectin, which can help with diarrhoea.
Ginger or peppermint tea
Studies have found that a soothing cup of your favourite herbal tea can do wonders to settle the nasty effects of food poisoning. Ginger tea is thought to reduce motion sickness, whereas peppermint tea is a known morning sickness cure in pregnancy. Both will also reduce nausea and stomach pain.
Foods with a high-water content
Since food poisoning can leave the body very dehydrated, it is important to try to retain as much water as possible. In addition to the various drinks, foods that are high in water will help as well.
Once you are ready to try food again, some good options are celery, tomatoes, aubergine, radishes, strawberries and the obvious cucumber and watermelon. All of these fruits and vegetables contain around 80-95 per cent water, and are also filled with natural sugars, important vitamins, such as vitamin A, B, and C, and minerals, such as potassium and magnesium.
When to see your doctor about food poisoning
If symptoms persist or become more serious, contact your doctor. ‘If you are repeatedly vomiting, pass bloody stools, or have a high temperature then you should see your GP,’ says Ernestam.
‘Also, if you are experiencing symptoms of severe dehydration, such as not passing urine, dry mouth, or difficulty keeping fluids down, then call your GP.’
Most food poisoning infection will clear up within a week but if you aren’t starting to get better after a few days or are becoming significantly dehydrated then you should speak to your doctor. Similarly, pregnant women, young children, elderly people and those with underlying medical conditions or weak immune systems may be more severely affected and should contact their doctor if they have food poisoning.
How can food poisoning be prevented?
There are a few things you can do that will help you to avoid getting food poisoning. These include the following:
Wash your hands
Make sure you wash your hands thoroughly and regularly with warm water and soap. Always wash them after going to the toilet, before eating, after handling pets and before and after preparing food.
Follow use-by dates
Even if the food looks okay, don’t eat it if it has passed it’s use by date.
Cook food properly
Make sure all food, particularly meat, is always cooked through before eating it. Ensure pre-cooked food is reheated adequately.
Cool down leftovers
If you’re saving a portion of food, make sure it’s throughly cooled down before putting it in the fridge or freezer. However, don’t leave it out for hours.
Store food correctly
Check the instructions on food labels to ensure it is stored at the right temperature. Keep raw meat covered and on the bottom shelf of the fridge so it doesn’t drip down and contaminate other foods.
Is food poisoning contagious?
Even if it’s food poisoning, it’s best to assume that you are infectious for as long as you have symptoms and take extra care with hand washing after using the toilet and before preparing or eating food. You should also avoid preparing food for others wherever possible until the diarrhoea has settled.