Queen Elizabeth II, the 86-year-old British monarch, was admitted into the hospital Sunday with a stomach illness, news sources reported.
The queen was taken to King Edward VII Hospital in London, the BBC reported. All of her official engagements for the week have been canceled.
She is apparently suffering from gastroenteritis, which typically clears up after one or two days, the Associated Press reported.
Elizabeth II has held the throne for 61 years, according to the New York Times. She was last hospitalized in 2003 for knee surgery.