As many as 28 cases were reported initially, but by yesterday the number of people with health problems had jumped to over 100 of the 800 guests.
The poisoning has escalated so quickly that a field hospital has also been set up at the seafront hotel.
Guests have been struck down with nausea, vomiting, diarrhoea and even fever in some cases following a lunch at the hotel.
All children were taken to Santa Lucia Hospital in the nearby port city of Cartagena to be treated.
Health inspectors have taken samples from the kitchen at the hotel, which has now been closed, as part of an ongoing investigation.
Regional government health sources said overnight they were treating it as a probable salmonella poisoning outbreak.
Gergana Krasteva and Natalia Penza