Changing instrumentation by page?

I'm writing an SATB choral piece. In some parts of the song the SA and TB parts have the same rhythms, and in other parts each section has different rhythms. Is there a way to separate the instrumentation of a piece by page (e.g. pages 1-3 have SA and TB grouped together while pages 4-7 have SATB each as separate bars)? Thanks in advance!