LONDON (CNN) -- Britain's Queen Elizabeth II will miss a service celebrating the Commonwealth Monday, as she continues to recover from an illness that left her hospitalized last week, Buckingham Palace announced in a statement.
The 86-year-old monarch was admitted to a London hospital on March 3 with symptoms of gastroenteritis, an inflammation of the lining of the stomach and intestines, before being released the following day.
A palace source told CNN the queen's health problems are "nothing serious" and "nothing to fret about," despite preventing her attending the Commonwealth Observance service at London's Westminster Abbey.
The queen will still attend Monday evening's Commonwealth Reception at Marlborough House, the statement said, where she will sign a new charter calling for equal rights in all Commonwealth nations.
The charter, adopted in December by all 54 countries over which the queen nominally presides, declares: "We are implacably opposed to all forms of discrimination, whether rooted in gender, race, colour, creed, political belief or other grounds."
While some observers believe the queen's signing of the Commonwealth Charter signals her implicit support for gay rights and women's equality, a Buckingham Palace official said the monarch is merely carrying out her official duties.
The official said: "The Queen is apolitical and is signing the document in her capacity as head of the Commonwealth."
The 16-point charter also embraces democracy, freedom of speech and the rule of law among its provisions.
The charter's principles could be difficult to implement in many Commonwealth countries, like Uganda, where homosexual acts are currently illegal.
Prince Philip, the queen's husband, will attend the ceremony at Westminister Abbey, where a recorded message from the queen will be played.
In the message the queen declares: "Our shared values of peace, democracy, development, justice and human rights -- which are found in our new 'Commonwealth Charter' -- mean that we place special emphasis on including everyone in this goal, especially those who are vulnerable."
A Palace official said the queen, who celebrated her 60th year on the throne in 2012, hopes to undertake some of her official engagements planned for the rest of this week.
™ & © 2013 Cable News Network, Inc., a Time Warner Company. All rights reserved.