I do not think Mestinon would have adverse effect on patient without MG. It is also used, outside MG, to improve bowel transit and in France, you may have it for that purpose without prescription.
Also, as far as Gulf war side effects are concerned, I think the dose given to GI's was around 30 mg/day which is ridiculously low for us, MG'ers and also during a much shorter time...
Maurice.