Our brick fireplace is rolling smoke back into the house.?

The chimney may have been sized down to accommodate the wood stove. Also, there may have been blocks put in so the smoke from the wood stove didn't go down instead of up. Have someone knowledgeable specifically in chimneys inspect it if you want to use the fireplace instead of the wood stove. They should be able to tell you what modifications may have been put in that you will need to remove.