Methods and devices are provided for treating multiple interval well bores. More particularly, an isolation assembly may be used to allow for zonal isolation to allow treatment of selected productive or previously producing intervals in multiple interval well bores. One example of a method for treating a multiple interval well bore includes the steps of: introducing an isolation assembly to a well bore, the isolation assembly comprising a liner, one or more sleeves and a plurality of swellable packers, wherein the sleeves and swellable packers are disposed about the liner; deploying a shifting tool inside the liner, where the sleeves are configured so as to provide open, closed and open to screen positions when actuated by the shifting tool. An open position allows for treatment of the well bore while an open to screen position allows for receiving fluid from the well bore. A closed position re-establishes zonal isolation.