Seems like the oxides of magnesium are problems. Would this be true for magnesium peroxide (MGO2) as well? There is a laxative alternative product that uses this as the only ingredient. Would it also be a problem with the intestinal walls as is mag oxide?
No, magnesium peroxide is way different. Magnesium oxide will form magnesium hydroxide when mixed with water. This burns the intestinal wall. Magnesium peroxide decomposes releasing oxygen. So it is not caustic like the hydroxides.