LOS ANGELES, California (CNN) -- Paris Hilton was let out of jail Thursday morning, days after she began serving what was to have been a 45-day sentence for violating probation, a spokesman for the Los Angeles County Sheriff's Department said.

Hilton must wear a monitoring bracelet and remain at her home for another 40 days, said sheriff's department spokesman Steve Whitmore.

Medical considerations "played a part" in the decision to offer Hilton home confinement for the remainder of her sentence, Whitmore said. (Watch Whitmore detail Hilton's deal )

He said privacy rules prohibited him from giving details about the medical issues, but celebrity Web site TMZ.com earlier quoted sources saying Hilton was refusing to eat much of the jail food served her.

Whitmore said that after "extensive consultation with medical personnel" it was decided to offer Hilton "reassignment" to home confinement, which she and her attorneys accepted. (Watch Hilton enter jail )

Part of the deal was that her original sentence of 45 days, which had been reduced to 23 days if she showed good behavior behind bars, would be restored to the full length. Although she reported to the jail just before midnight Sunday and departed in the early hours of Thursday, she was given credit for five days, he said. (Blog: Is this a miscarriage of justice?)

Whitmore said the decision to send Hilton home was made by a panel of officials in the sheriff's department, although the judge who sentenced her was advised of the move.

Hilton was arrested on charges of drunken driving in September.

In January, she pleaded no contest to a charge of alcohol-related reckless driving. She was sentenced to three years' probation and had her license suspended.

In February, she was caught driving on a suspended license, which later was ruled a probation violation.

Hilton entered jail Sunday after attending the MTV Movie Awards, where she answered questions from the press and was the subject of host Sarah Silverman's jokes.