Janice Dickinson and Rachel Uchitel were roommates on Celebrity Rehab 4 but the arrangement didn't last very long and the feuding duo had to be separated by staff, RadarOnline.com learned exclusively.

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According to a show insider, the two "were practically at each other's throats from the beginning. They fought constantly, and Dr. Drew and the staff ultimately made the decision to separate the two as they were just being so disruptive to everyone involved. It was just way too much ego in one room.”

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As RadarOnline.com previously reported, Rachel bolted from the show for 24 hours, holed up at a swanky Beverly Hills hotel, but and was lured back by producers the next day. "Rachel just couldn't stand even being in the same vicinity as Janice, and the tension that Rachel was dealing with because of it was one of the reasons that she left,” the insider added.

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“Janice was hoping she wouldn't come back, but Janice predicted that Uchitel would ultimately comeback because she missed the cameras. It drove Janice over the edge that Rachel thought she was a celebrity. Both of these women are dealing with major self esteem issues, along with their personal addictions.”

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The cast graduated earlier this week with Jason Davis, Jeremy London, and Jason Wahler continuing inpatient treatment at another facility, RadarOnline.com has confirmed. BET reality TV star Frankie returned to Atlanta and is preparing to enter an after care center there. Neither Rachel nor Janice are continuing treatment in a facility, but both are following a care plan that was given to both of them.

Celebrity Rehab 4 is scheduled to premiere in October on VH1.