Dr Pall has done wonderful work in showing that MCS, CFS and FMS (and other illnesses in this group - even MS) have very similar biochemical problems in the body. He has proven that you CAN do tests to show that a person has real things wrong with them. This shows there is hard science about how real MCS is, but as for the -cause-

All of the diseases that come with chemical sensitivity (including Altzheimers and Autism) seem to also come with an inflammatory problem in the gut, which causes poor absorption (leaky gut syndrome) - and that leaves the body starved for nutrients no matter what you eat. The entire body breaks down.  It is like pouring water into a bucket without a bottom on it.

Worse yet, this harms the lymphatic systsem.

This can easily produce a reinforcing cycle of gut flora dysbiosis, and although bad gut flora can keep the process going, and can help in compromising the gut wall - bad gut flora does not start the process. It is a symptom of an earlier problem. The problem starts with the world that we live in today, and the foods most of the western world is eating. POLLUTION, and food that is not really food.

This link talks about the link between lymph and the small intestine. Do some searching and learn

www.ncbi.nlm.nih.gov/pmc/articles/PMC3064563/

This link explains a lot more of it (but not everything)

http://joannebrophy.com/system/lympathic.htm

The page has a lot of facts about how the lymphatic system works. I don't know if the "treatment" ideas have any merit. I do know that MY lymphatic system is very poisonous right now & my wife has this problem too.  My legs hurt a lot today. The left one is burning and burning.

The same set of problems (most of them spawned from greed) lie at the heart of our modern plagues. We need to stop pushing for every last dollar, and start making decision based on what we want life to be like in another 20 generations.