These can start almost straight away, or they can take as long as three days to appear. Symptoms usually include at least nausea and some stomach upset - recurring cramps are typical - and probably diarrhoea. If this is fairly mild it will probably go away on its own.

If the attack is more severe, you may also experience a shivering feeling, or a high temperature, or sometimes both alternately. You will probably lose your appetite and may have pains in other parts of the body besides the stomach. If you have these symptoms you will probably need to rest until they subside.

Generally, food poisoning should start to get better after two days (a mild attack may only be for one evening.) If you are still being sick after three days, or even less if you are vomiting up liquids too, then you should see a doctor. Other worrying symptoms include blood in your stool or vomit, extreme dehydtration or feelings of confusion. You can find a detailed list of symptoms here.
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