LONDON – Britain’s Queen Elizabeth II was hospitalized Sunday over an apparent stomach infection that has ailed her for days, a rare instance of ill health sidelining the long-reigning monarch. Elizabeth will have to cancel a visit to Rome and other engagements as she recovers, and outside experts said she may have to be rehydrated intravenously.

Buckingham Palace said the 86-year-old queen had experienced symptoms of gastroenteritis and was being examined at London’s King Edward VII Hospital – the first time in a decade that Elizabeth has been hospitalized.

“As a precaution, all official engagements for this week will regrettably be either postponed or cancelled,” the palace said in a statement. Elizabeth’s two-day trip to Rome had been planned to start Wednesday. A spokeswoman said the trip may be “reinstated” at a later date.