HOW LONG DOES IT TAKE?

Food poisoning to develop: Five days FOOD poisoning symptons appear within hours of eating contaminated food such as undercooked sausages and meat, ‘but the most common infection in the UK is campylobacter, which has an incubation period of two to five days’, says Dr Anthony Hobson, a gastroenterologist from the Functional Gut Clinic in London.

‘Another common cause of upset stomach is norovirus, which you catch directly from an infected person or food touched by them. This can take three days to produce symptoms,’ he adds. Whatever the cause, treatment is simple: ‘don’t eat for 24 hours, keep hydrated with small, regular amounts of water and don’t take medication to stop bowel movements, as this prevents the body expelling the bacteria,’ says Dr Hobson. ‘If symptoms persist for more than two days, see a doctor.’