According to the BBC, the 86-year-old monarch was "in good spirits" while on her way to the hospital this weekend.
In speaking with the news agency, a spokesman for the Queen called the trip "a precautionary measure" for the Queen who was said to be healthy besides her stomach bug. "She was not taken into hospital immediately after feeling the symptoms. This is simply to enable doctors to better assess her," added the spokesman.
The Queen was expected to stay in the hospital for about two days, according to Peter Hunt, the BBC's royal correspondent, but was released on Monday instead.
This news follows Prince William and Duchess Kate's appearance at a weekend wedding in the Swiss mountains.