CHICAGO (CBS) — Riccardo Muti arrived in Chicago just weeks ago amid a wave of fanfare, which was followed by stellar reviews.

But the new conductor of the Chicago Symphony Orchestra is already putting down his baton, for now.

Muti, 69, withdrew from the CSO’s gala “Symphony Ball” on Saturday because of illness. He “is suffering from extreme gastric distress,” a release from the orchestra said.

Muti was leaving by plane for Milan Monday to be with the doctors who speak his native language and who have been treating him for this ailment for a period.

He was apparently ill enough Saturday that doctors were standing by at his scheduled performance, a performance he was forced to abandon.

If all goes well, the $2 million-a-year conductor is expected to return in late January to begin rehearsals for a February residency, which kicks off with a Feb. 3 performance, the symphony’s press office said. Muti also has scheduled residencies in the spring as part of his five-year contract, the CSO said.

The Civic Orchestra of Chicago’s open rehearsal with Muti in Pilsen scheduled for Saturday, Oct. 9, has been postponed to a future time to be announced, according to the release.

“I cannot express the depth of my regret that I am unable to complete this first residency as music director,” Muti said in a written  statement. “I have had the privilege of making marvelous music together with this great Orchestra, and I am confident that we will continue to do so when I return again.”

Muti’s departure comes after a CSO media blitz trumpeted him and his new relationship with Chicago. His absence was felt Monday, at a CSO activity for Chicago students. He was instrumental in organizing new outreach programs, but the CSO knows the show must go on.

The CSO will find substitute directors and remain committed to Muti’s vision of sharing his art. Just last week, he was teaching music to teen-agers in jail.

Muti’s free debut concert before 25,000 at Millennium Park was a hit, but managers quickly noticed the 69-year-old was ill. They later learned it was a persistent stomach disorder.

“I was able to see that he was not feeling well and he was very discreet and he didn’t want to burden us because he knew how much was riding in these concerts,” Deborah F. Rutter, president of the Chicago Symphony Orchestra Association, said.

Muti first conducted the CSO in his 30s, and his return to the city had been highly anticipated.

CBS 2′s Vince Gerasole, Sun-Times Media Wire and The Associated Press contributed to this report.