Francis went to a department in the hospital specialised in treating elderly patients and arrived at 1040 local time (0840 GMT) before being driven away at around 1120, the reports said.

There was no immediate comment from the Vatican.

Francis spent five days in the same hospital at the end of March with a lung infection and last month skipped audiences on one day due to a fever.

Francis, who marked the 10th anniversary of his pontificate in March, has suffered a number of ailments in recent years and often uses a wheelchair or a cane to walk because of persistent knee pain.

In July 2021 he had part of his colon removed in an operation aimed at addressing a painful bowel condition called diverticulitis. He said earlier this year that the condition had returned.

The pontiff is also missing part of one lung, which was removed when he was a young man in his native Argentina.

Despite his health issues, Francis maintains a busy schedule. The Vatican announced plans on Saturday for him to visit Mongolia on Aug.31-Sept.4, one of the more remote places he has travelled to.

Before that he is due to visit Portugal from Aug. 2-6 to attend the World Youth Day in Lisbon and visit the Shrine of Fatima. The Vatican on Tuesday released an official schedule for the trip, giving an indication it was confirmed.

(Reporting by Gavin Jones, writing by Gavin Jones and Keith Weir, editing by Crispian Balmer)