It may not be due to your last meal
Often, if people become ill in this way just after eating at a
restaurant or ready-cooked food bought from a shop they will be
sure that this is the cause.
But, food poisoning bacteria take quite a long time to reproduce
inside the human gut and some people are more resistant than others
so it may be some time before there are enough to cause
illness.
Very often it can be something eaten as long as two, even three,
days before the symptoms show, which caused the problem.
Some food poisoning symptoms can appear more quickly. This is
usually caused by the poison or toxin which some bacteria make. If
there is a lot of this in the food when eaten the stomach is likely
to react quite quickly by vomiting to try to remove the poison.
This can happen within a few hours of eating the affected food.
Another very fast acting type of food borne illness is that
of allergic reaction. This can vary from unpleasant tingling in the
mouth and rashes to anaphylactic shock and
death.