US Supreme Court Justice Ruth Bader Ginsburg has been taken to hospital in Maryland “for treatment of a possible infection”, the court has said.
It said in Baltimore’s Johns Hopkins Hospital she “underwent an endoscopic procedure… to clean out a bile duct stent that was placed last August”.
Ms Ginsburg, 87, was “resting comfortably” and would stay in the hospital for a few days.
As the court’s most senior liberal justice, her health is closely watched.
She has received hospital treatment a number of times in recent years, but has returned swiftly to work on each occasion.
In May, she took part in legal argument from her hospital bed, just a day after she was admitted with a gallbladder condition.
In August 2019, Ms Ginsburg was treated for a cancerous tumour on her pancreas. She received treatment for colon cancer in 1999, and pancreatic cancer in 2009.
And in December 2018, she had surgery to remove two cancerous nodules from her lung. She has also suffered fractured ribs from falls.
Supreme Court justices serve for life or until they choose to retire, and supporters have expressed concern that if anything were to happen to Ms Ginsburg then a more conservative judge might replace her.
President Donald Trump has appointed two judges since taking office, and the current court is seen to have a 5-4 conservative majority in most cases.