The new music director for the Chicago Symphony Orchestra will miss the rest of his performances this fall. Riccardo Muti fell ill with “extreme gastric distress.”

Riccardo Muti’s flying back to Italy this afternoon for treatment. The president of the CSO association, Deborah Rutter, says Muti’s been sick for a few weeks.

But she says his illness peaked Saturday before a sold-out gala, leaving the guest violinist to help lead the orchestra.

RUTTER: I promise you, the great aggravation Maestro Muti is experiencing right now is his own frustration he can’t be here. He is very, very upset that he can’t stay and do this work. But it was with consultation of physicians here in Chicago that the final decision he would return to Italy was taken.

Muti’s inaugural season’s been greeted with great excitement. He conducted to an overflow crowd at Millennium Park just two weeks ago.

The show will go on without him. The CSO has tapped three guest conductors.