After spending only spend 72 hours in the pokey, Paris Hilton has been released from behind bars.

The 26-year-old The Simple Life star was released from the Century Regional Detention Facility shortly after midnight on Thursday, only three full days after she began serving a minimum 23-day sentence Sunday night for violating her probation on a September 2006 drunken driving misdemeanor. 

However Hilton isn't completely off the hook, as Los Angeles Sheriff's Department spokesman Steve Whitmore told reporters during a Thursday morning news conference that the hotel heiress had been diagnosed with "medical issues" that resulted in her being "reassigned" to house arrest for the next 40 days, according to E! Online.

"After extensive consultation with medical personnel including doctors here at CRDF, it was determined that Paris Hilton would be reassigned to our community-based alternative to custody electronic monitoring program," said Whitmore, E! reported.  "She has been fitted with an ankle bracelet. And she has been sent home. And she will be confined to her home for the next 40 days. Because she has agreed to this through her attorney, her sentence is now back up to 45 days. She has served already five days, so that's 40 days."

Following her DUI last September, Hilton got off pretty lightly with three years' probation and the requirement that she "obey all laws" and enroll in alcohol education classes within 21 days.  But she was arrested once again in Los Angeles for driving without a valid license in February, which led prosecutors to recommend that she serve time behind bars for violating her earlier probation from the DUI. She was sentenced to 45 days in jail for violating her probation and was required to report to jail by Tuesday, June 5.  

After her sentence was announced, Hilton denounced it as "cruel and unwarranted," filed an appeal and petitioned California Gov. Arnold Schwarzenegger for a pardon.  Jail officials eventually reviewed Hilton's case and -- citing overcrowded jail conditions and a California statute that grants credit for good behavior -- informed her she would only have to serve "at least 23 days" for the parole violation, according to E!.

Hilton "turned herself in" only a few short hours after attending the MTV Movie Awards late Sunday night to begin serving her sentence as inmate 9818783, according to E!, before being released Thursday morning and confined to her home for the next 40 days.