A holiday park has been closed after an outbreak of Norovirus that affected up to 90 guests.
Children and adults at Mullion Holiday Park in Cornwall reported diarrhoea and vomiting.
Bosses have ordered accommodation and public areas in to be professionally cleaned, and refunds have been offered.
The outbreak was first reported publicly on Thursday, although some guests at the park on the Lizard were suffering with symptoms on Wednesday.
The decision to close was taken on Friday morning, with a spokesperson calling it a "precautionary measure".
One mother, who didn't wish to be named, said her 13-year-old son was diagnosed with Norovirus after being admitted to hospital on Wednesday night.
She said: "It's been hideous. I don't blame the park because these things can happen but it could have been managed better.
"If we had known about the outbreak earlier we would have had the option not to use the shared facilities or be more vigilant."
She also said children were projectile vomiting in public areas but deep cleaning procedures did not appear to be in place.
Public Health England (PHE) said it is working the Cornwall Council to investigate the outbreak.
Dr Bayad Nozad, from the PHE said Norovirus had been confirmed: "The virus usually leads to mild diarrhoea, vomiting and abdominal or stomach cramps that people recover from quickly.
"There is no specific treatment but, if affected, it is important to drink plenty of water to avoid dehydration."
The holiday park, run by Parkdean Resorts, has indoor and outdoor pools, a bar, an arcade and restaurant and an entertainment venue.
It is seeking to find alternative accommodation for guests and offering refunds for those whose holiday has been cut short.