Because my body was never intended to synthesize or metabolize that natural solution either.
So all the people that have used aloe vera through the ages should have died or suffered like dogs all the time?

I don't get it.
You can be against natural products, if that's your thing, but if I am constipated I'll first try more fruit and vegetables in my diet, adding other natural remedies along the way if needed, and leave the chemicals alone for as long as I can. I don't want to put in my body something that has to come with a leaflet explaining the side-effects and interactions.
As for the quantity ingested, excuse me, but if you (general "you", of course) don't understand that too much of -any- given thing will harm you, you should be left to die by your own hands and stupidity. You know how it is, natural selection and all that jazz.
Chemically synthesized medication is stringently tested on large number of individuals in every age group. Its side-effects and interactions with other medication are documented, and are reflected in labelling. No offense to grandma's folk lore, but I very much doubt she ever used control groups.
Nope, no groups, just common sense. Which before the invention of controlled groups did a good job of keeping the species alive for a few thousand years.
Chemically synthesized medication is also 'pure'; it contains the active substances, and nothing else that might affect your body.
Then why the need for a label/leaflet?
Again, if natural products are not your thing, it's ok, it's your business and please do give the OP any advice you consider sound and useful, but as far as I am concerned, I'd rather give advice about something that I have tried, that is natural, and that doesn't need a leaflet an arm long. And that's my business. I don't bash your personal choice, you don't bash mine, we're all friends.