[Coda]

Pesticides don't have to add chemicals to diatomaceous earth. They use it directly. Some products are pesticide MIXES, yes, but that doesn't mean that diatomaceous earth isn't a pesticide on its own.

The FDA recognizes it as GRAS for purposes such as skin scrubs and toothpaste, where the micro-abrasive properties of the stuff are the entire purpose of using it. But just because it's safe to accidentally swallow a small amount of toothpaste doesn't mean it's a good idea to intentionally consume more of it -- the GRAS rating is specifically about it being safe to use it in the way that was evaluated but it makes no guarantees about it continuing to be safe if you go outside of the recommendations.

And yes, as you said, a GRAS rating doesn't say anything about it being effective, just about it being not likely to kill you.

Given the description your problem may actually be too much fiber, especially insoluble fiber. You need a certain amount of soluble fiber in your diet, so don't cut it out entirely, but loading up on extra fiber when your problem is that your stool isn't binding together in the first place is going to result in having to pass more loose stool instead of solving the problem -- as you've found out the hard way.

You should also cut back on fried food, chocolate, caffeine, and carbonated beverages, and you should be careful with too much fruit or honey. These all make diarrhea worse, and it's speculated that the rise of IBS and IBS-like symptoms is a result of the increase in these things in the typical American diet.