Pope Francis went to a Rome hospital on Sunday for scheduled surgery on his large intestine, the Vatican said. The news came just three hours after Francis had cheerfully greeted the public in St. Peter’s Square and told them he will go to Hungary and Slovakia in September.

The brief announcement from the Holy See’s press office didn’t say exactly when the surgery would be performed at the Gemelli Polyclinic, a Catholic teaching hospital, but said there would be an announcement when the surgery is complete.

The Vatican said the 84-year-old pope had been diagnosed with “symptomatic diverticular stenosis of the colon,” a reference to a narrowing in the large intestine. The surgery was to be performed by Dr. Sergio Alfieri, the director of Gemelli’s digestive surgery department.

A week earlier, Francis had used his same Sunday appearance to ask the public for special prayers for himself, which, in hindsight, might have hinted at the planned surgery.

“I ask you to pray for the pope, pray in a special way,” Francis had asked the faithful in the square on June 27. “The pope needs your prayers,” he said, adding his thanks and saying “I know you will do that.”

Francis is in generally good health, but did have part of one lung removed as a young man. He also suffers from sciatica, occasionally having painful bouts of the condition in which a nerve affects the lower back and leg. That has forced him at times to skip scheduled appearances.

The pope had a particularly demanding set of appointments last week, including celebrating a Mass on Tuesday to mark the Catholic feast day honoring Saints Peter and Paul, and later in the week, presiding at a special prayer service for Lebanon. On June 28, he also had a long private audience at the Vatican with U.S. Secretary of State Antony Blinken. Throughout all those engagements, Francis appeared to be in good spirits.

Gemelli doctors have performed surgery before on papal patients, including on Pope John Paul II, who had a benign tumor in his colon removed in 1992.