Pope Francis has been admitted to a hospital in Rome for scheduled surgery to treat a colon problem.
Vatican spokesman Matteo Bruni said there would be more information after the surgery had taken place at the Gemelli University Hospital.
Earlier on Sunday, the 84-year-old Argentine Pope addressed thousands of visitors in St Peter’s Square.
This is the first time the pontiff has been admitted to the hospital since his election in 2013.
In its statement, the Vatican said he was being treated for “symptomatic diverticular stenosis” of the colon.
Diverticular disease is a condition that involves bulges in the wall of the large intestine. This can lead to a narrowing, of the colon.
During his Sunday’s blessing in St Peter’s Square, the Pope announced that he would go to Slovakia in September after celebrating Mass in Budapest, the capital of neighbouring Hungary.
Born in 1936 in Buenos Aires, Francis lost part of his right lung at the age of 21.
He also suffers from a hip problem and sciatica, which causes pain that radiates from the lower back to the legs.
In 2014, he had to cancel a number of engagements because of a reported stomach ailment.
Symptoms include bloating, recurrent abdominal pain, and changes in bowel habits.