Check saliva pH. Most with FMS have a problem with all clear fluids in the body being very acidic. Saliva pH needs to stay at about 7.0 for the body chemistry to function correctly.
Get little paper test strip paper dispenser at your local health food stores. They think it's just for urine, but we only test saliva pH.
www.FibroFix.com is an all free site. Tells how to test, what to not eat, etc.