A US pharmaceutical company has come up with a novel way to get people to participate in trials for a remedy for “holiday tummy”. Intercell is offering up to 900 volunteers free holidays to Mexico or Guatemala - and all they need to do is eat, drink and see if they get sick.

The holidays are worth up to £1,400 and include flights and accommodation in three-star hotels. Travellers can go where they like, as long as they remain within three hours of test centres where they must provide blood and stool samples if they are struck down with a stomach upset.

Participants need to wear a patch on their arm for six hours, three weeks prior to travel, followed by another the week before travel, then take their holiday as planned and see if they get sick.

Recruitment clinics are opening in London, Manchester, Birmingham, Belfast and Glasgow.

Thomas Lingelbach, chief executive of Intercell, told The Independent: “We need to show the vaccine is effective in different geographical settings, as the bacteria that cause diarrhoea are different in different regions.”

“If we can show broad coverage against travellers’ diarrhoea we estimate we could get peak sales of 500m a year in five to 10 years.”

The vaccine has already been tested on American volunteers who travelled to Mexico and Guatemala, and results showed the drug reduced incidents of diarrhoea by 75 per cent.

Those interested in taking part can find more info at www.trekstudy.com.