Queen Elizabeth II of Britain has been admitted to hospital in London after experiencing symptoms of gastroenteritis, Buckingham Palace said today.
She had been due to visit Rome for two days this week, but the trip has been cancelled.
"The Queen is being assessed at the King Edward VII's Hospital in London, after experiencing symptoms of gastroenteritis," a palace spokesman said.
"As a precaution, all official engagements for this week will regrettably be either postponed or cancelled."
Downing Street said that British prime minister David Cameron had passed on his best wishes to the Queen.
On Friday night Queen Elizabeth cancelled a planned visit to Wales after suffering from symptoms of gastroenteritis. She was due to attend a military celebration in Swansea today for the city's St David's Day celebrations.
She has rarely missed a royal engagement due to ill health.
She pulled out of an investiture ceremony last October after suffering a bad back. The 86-year-old monarch also missed a visit to the British Museum in 2011 because of a cold.
PA