I take Swiss Kriss. Have taken Colon Clenz before too which has Cascara Sagrada in it as well and is too harsh for me to take daily. These are both available at the healthfood stores. Swiss Kriss is made by Gayelord, ther is no Phone listed on the bottle but I would be happy to send you some if you can't find them.
I know the nausea is no fun at first, hopefully that will subside and pass soon for you.
Love you lots,
Janet