Here's why: The writers will have Christine in Australia and her mother, Mary, goes Down Under to visit her. Therefore, Bell will not have any scenes with any other Genoa City residents.
Bell has made occasional appearances since taking an extended maternity leave in December 2000. Her most recent return came in November 2001 when she returned for the funeral of Ryan McNeil.
Rumors persist that Bell will be returning to the show full-time in the near future [See related article: "Damian's Return to Y&R Not a Done Deal"]
Bell's return two-day engagement is scheduled for March 21 and 22.