Perma Guard is very good quality DE, so I don't think that is your problem. Taking spoonfulls can have a dehydrating effect in the bowel, this is why its sooooo important to make sure your drinking lots of water.
When my friend started taking silica supps, she had strange sensations in her kidneys, (she is very prone to calcium kidney stones), this sensation was due to the action of the silica on the small calcium stones she had, they are now gone.