Aidan O'Brien's 2000 Guineas and dual Derby winner Camelot has undergone exploratory colic surgery, Coolmore have said.
The colt, who attempted to become the first Triple Crown winner in over 40 years at Doncaster last month where he just came up short, has been admitted to Fethard Veterinary Hospital.
Camelot ran in the Prix de l'Arc de Triomphe at Longchamp on Sunday where he finished seventh when ridden by Frankie Dettori.
A tweet from Coolmore Stud read: "Triple Classic winner Camelot was admitted to Fethard Veterinary Hospital this evening and underwent exploratory colic surgery.
"Obviously it is still very early days but a further bulletin will be released in the morning."