The Pope has been admitted to hospital to have an operation on his intestine.
It comes a day after the pontiff had medical tests at a Rome hospital.
The Vatican said the procedure would be under general anaesthetic on Wednesday afternoon and he would stay in hospital for “some days”.
It said the 86-year-old had been suffering “recurrent, painful and worsening” symptoms caused by a incarcerated laparocele (abdominal hernia).
The Pope spent time in hospital at the end of March due to a respiratory infection and last month had to skip audiences because of a fever.
Two years ago, he also had 33cm (13 inches) of his colon removed because of an inflammation and narrowing of the large intestine.
He is also missing part of one lung, which he had removed when he was a young man in Argentina.
Knee pain is also a problem for Francis, who marked his 10th year as pontiff in March, and he often uses a cane to walk.