Her official engagements for the week were postponed or canceled Sunday . NEW : London 's Elizabeth II is now out of Buckingham Palace Hospital . Gastroenteritis is an inflammation of the lining of the stomach and intestines . The illness can cause dehydration and kidney problems in the elderly , a doctor says . Queen Elizabeth II was hospitalized `` as a precautionary measure , '' Prince Philip says .
NEW : London 's Elizabeth II is now out of Buckingham Palace Hospital . Gastroenteritis is an inflammation of the lining of the stomach and intestines . The illness can cause dehydration and kidney problems in the elderly , a doctor says . Queen Elizabeth II was hospitalized `` as a precautionary measure , '' Prince Philip says .