Rizzo was released from Good Samaritan Hospital on Thursday night.
On Wednesday, he was rushed from the courthouse to the hospital after complaining of chest pains.
There was no word on his doctor's findings, but Rizzo plans to be back in court on Monday to continue his preliminary hearing on corruption charges.
Prosecutors allege Rizzo, 57, was the mastermind of a scam in which he and others stole millions from Bell by illegally inflating their salaries.