Question about OxyPowder ingredients

I need to do a colon cleanse, and am looking at the pros and cons of the popular ones out there. I liked the idea of the Oxypowder, since it didn't have herbs like Cascara Sagrada, which would cause dependency. So I have a question about the ingredients of OxyPowder....says the main ingredients are Magnesium Oxide. I was told that Magnesium is very bad for your kidneys, especially for diabetics who are trying to save their kidney function. Well, I guess this is a dumb question, but would the OxyPowder be very bad to take, just for a short time, to clear out the sludge of a clogged up colon? If so, then how long is a good time to take it? I know it has very large doses of Magnesium I saw.....isn't this very bad for kidneys then?? Tweet