"One thing that I think indicates something other than poisoning is that these reactions of diahrrea and nausea usually hit around 2-4 hours after injestion. Poisoning would presumably be much faster."
Yes, and also you would not then get better as you further increased the dosage later. If something is a poison, then it remains a poison, especially at higher concentrations.
The fact that so many have gotten so healthy using it over time suggests that the initial symptoms are indeed die-off ... temporary reactions to the very real poisons from pathogens...these include: Acetaldehyde, Uric Acid, Alloxan, Lactic Acid, Alcohol, Oxalic Acid, Cyclosporin, etc...
The range of symptoms produced by these and other endotoxins and exotoxins is truly staggering.