The television legend and his concerned wife Patti Newton spent seven hours in Epworth hospital in Melbourne on Wednesday.
Later that night a distraught looking Patti emerged to return to the family home, alone.
“Patti definitely looked stressed, like something was really up,” an onlooker at the scene tells Woman’s Day.
“She was far from her usual calm self.”
This latest dash to the ER comes after Bert was hospitalised for a serious bout of pneumonia in March, one of several times he has battled the potentially deadly infection.
“Bert has been ill on a number of unreported occasions,” a close friend of the pair tells Woman’s Day.
“The most notable time was his heart scare [in 2012] when hospitalised and immediately prepped for surgery. On that time they were prepared for the worst.”
“But Bert has a strong constitution, it leaves his family gobsmacked sometimes,” adds the Newton’s friend.
“He will rally and say, ‘Stop worrying, I’m OK’, when doctors least expect it. They don’t make them like Bert anymore.”
We’ll keep you updated as this story develops.