Charles Manson's in Bad Shape & Back In Prison

Charles Manson is back in Corcoran State Prison, and we're told he might not survive his health crisis.

TMZ broke the story ... Manson was taken to a Bakersfield hospital a week ago for significant intestinal bleeding. Doctors wanted to perform surgery, but Manson refused. Late last week he had a change of heart, but doctors determined he was so weak he might die on the operating table.

The surgeons went back and forth, planning the surgery again ... but ultimately cancelled it.

We're told there was nothing more the hospital could do, so Manson was taken back to Corcoran -- largely for security reasons.

As for the 82-year-old prisoner's condition, one source familiar with the situation said, "He's not good. His health is failing."