Queen Elizabeth II, who is 86, was admitted to a London hospital on Sunday after experiencing symptoms of gastroenteritis, according to a statement issued by Buckingham Palace.

The statement said that all the queen’s engagements for the next week would be postponed or canceled, including a two-day visit to Italy that was scheduled to begin Wednesday. She had already skipped one event, a military parade in the Welsh city of Swansea on Friday, because of the illness.

A palace spokesman described the queen’s hospitalization on Sunday as “a precautionary measure. sources said the queen was expected to remain in the hospital for about two days. Emphasizing that there had been no emergency, the palace said that the queen was taken to the King Edward VII Hospital in central London from Windsor Castle, a distance of 20 miles, by private car. Other than the gastroenteritis symptoms, the spokesman said, the queen was in good health and “in good spirits,” and she was moved to the hospital “simply to enable doctors to better assess her.”

When the news broke, a crowd of well-wishers gathered behind police barriers outside the hospital’s main entrance.