Anthony Kiedis Rushed to Hospital ... Red Hot Chili Peppers Gig Cancelled at Last Minute

The Red Hot Chili Peppers pulled the plug on a concert performance because lead singer Anthony Kiedis had to be rushed to a hospital.

RHC was set to play at the the Weenie Roast festival for KROQ-FM in L.A Saturday night ... when bass player Flea walked out on stage, and announced that Anthony would not be able to perform the show.

Word is Anthony was having stomach issues, and decided he wouldn't be able to play. We're told he left the venue in a Sprinter van.