GI neuroimmune disruption contributes to Gulf War Illness (2019)

That's interesting.

I and my two children returned to our Melbourne home from overseas and were fine for a month. Around the time that our personal effects arrived, there was a heat wave, days of 35 to 40 degrees centigrade. We stayed inside with the windows closed to keep the heat out, unpacking our boxes of things and with the furniture all smelling strongly of fumigants*. The fumigant used was methyl bromide and it was applied in a country where standards can be pretty lax to non-existent. At that time, the house didn't have a cooling system, and so it became very hot.

Soon after this, we developed gastrointestinal problems, a gastrointestinal flu we thought. My daughter was admitted to the hospital with suspected appendicitis and stayed there for three nights with very bad pain, but no problem was ever identified. And that was the beginning of our ME story.

I wonder if methyl bromide and pyridostigmine bromide act in a similar way. Early on, I did try to get the possibility of a poisoning as a result of the fumigant considered but no one was interested. I have mostly moved away from the idea as so many people have ME symptoms and didn't have fumigant exposure. But when things like this come up, I do wonder.

Pyridostigmine bromide is a cholinesterase inhibitor. This review suggests that methyl bromide might be a cholinesterase inhibitor:

A 2012 study:

Two epidemiological studies have analyzed environmental, non-occupational exposure to methyl bromide providing evidence for its health risk to the general public. None of the epidemiological studies addressed its use as a fumigant in freight containers, although recent field and case reports do refer to its toxic effects associated with its use in shipping and storage.

Conclusions
Both the epidemiological evidence and toxicological data suggest a possible link between methyl bromide exposure and serious health problems.... The environmental risks of methyl bromide are not in doubt, but also its health risks, especially for genetically predisposed subjects, should not be underestimated.
​

Edit - * I'm aware methyl bromide is odourless - the strong smell was the result of its reaction with the sulphur in proteins in things like wool and leather.