Troubled actor Tom Sizemore is heading back to reality show rehab after his most recent drug bust — and he’ll be coming face-to-face with former girlfriend, Hollywood madam Heidi Fleiss.

Tom was convicted of assaulting Heidi in 2003.

The Saving Private Ryan star has struggled with substance abuse problems for several years and was arrested on an outstanding warrant in Hollywood last Thursday, at which point he was found to be in possession of narcotics.

A source tells RadarOnline.com, “(Tom) showed up wasted yesterday at the Pasadena Recovery Center and was put in ‘lock down’ for serious withdrawals.

“Heidi… went straight to her room and didn’t comment.”