By Philip Pullella

The 84-year-old pope is expected to stay in hospital for seven days barring any complications, following his three-hour operation on Sunday night by a 10-person surgical team at Rome’s Gemelli hospital, spokesman Matteo Bruni said in a statement.

The pope underwent a left hemicolectomy, a procedure in which one side of the colon is removed, Bruni said. It was the first time the Vatican had disclosed the specific nature of the surgery.

The statement did not specify whether the decision to remove part of the colon had been taken before or during the surgery.

The scheduled surgery was for symptomatic diverticular stenosis of the colon, a condition in which sac-like pouches protrude from the muscular layer of the colon, leading it to become narrow.

In addition to causing pain, the condition, which is more common in older people, can lead to bloating, inflammation, and difficulty in bowel movement.

It was the first time Francis has been hospitalised since his election as pope in 2013.

The surgery appeared to be timed to coincide with a period in which he has only one public commitment – his Sunday blessing in St. Peter’s Square.

Francis traditionally suspends all his general and private audiences for the month of July, although unlike predecessors, he stays in the Vatican and has never used the sprawling papal summer estate in the cooler Alban Hills, south of Rome.

The Vatican said it was not clear if Francis would leave the hospital in time to make his Sunday blessing as usual. The late Pope John Paul led the prayer from the window of his room and even from his bed during several hospitalisations over the course of his 27-year papacy.

Information about Francis’ health has come via short Vatican statements, a contrast to John Paul’s time, when doctors issued detailed medical bulletins and even held news conferences. The guidance is believed to come directly from the pope, who guards his privacy more closely than John Paul did.

The sprawling Catholic-run Gemelli hospital and medical school in the northern part of Rome traditionally treats popes and a part of its 10th floor is permanently reserved for them.

Francis’ hospitalisation on Sunday came as a surprise because only hours earlier he appeared to be in good health when he addressed thousands of people in St. Peter’s Square and announced a September trip to Slovakia and Budapest.

Francis is sometimes short of breath because part of a lung was removed following an illness when he was a young man in his native Argentina.

He also receives regular physiotherapy for sciatica, which causes pain that radiates from the lower back to the legs. The condition forced him to miss several events at the beginning of this year and has led him on occasions to walk with difficulty. (Reporting by Philip Pullella; Editing by Alison Williams, Peter Graff and Catherine Evans)