The bishops had welcomed a circular by Niamh Bhreathnach, education minister, urging all schools to introduce RSE programmes next autumn. Their statement, however, said any such programme should be taught in the context of religion classes.
But the suggestion has been rejected by the three main teacher unions. One said such a move would be "illogical", while the others said RSE would be more acceptable to students if it were removed from the religion classes. The National Parents' Council argued that it should be done in the context of social and health education.
Guidelines will be issued to schools by the education minister on what such a programme might contain, but the Roman Catholic Church is to issue its own suggestions, too.
The bishops said that a religion textbook for schools was being revised and would incorporate a sexuality education programme.
Ultimately, however, it will be up to schools to decide how to introduce RSE. The minister's circular was less prescriptive than had been signalled last year, when she indicated that she favoured mandatory RSE in all schools.
A leaked report from her advisory body, the National Council for Curriculum and Assessment, had stated that there were legal and constitutional implications where parents wanted to withdraw their children from such classes.