Pain is a core symptom of an inflamed CNS. Curiously, the IOM left this out as it allows too much focus and research on people with probable ME (organic CFS), who were healthy before autoimmunity attacked their brains in response to pathogens and zonked their brains into sleep mode when awake as just one effect of this.
Without doubt, It's good the psychobabble isn't a focus of the IOM, but instead it's in the P2P.

. The P2P is the mother-in-law of Oxford CFS evidence based reasoning.
Basically, since we've been ill, all we have is Gov't time wasting exercises. ME>PVFS>CFS>SEID.
That's 1969 - 2015 = 46 years. Approximately the time for a Govt employer to be employed, awarded, then retire on a handsome golden hand shake, and the same time the poor patients never got to live their live before expiring from overwhelming disease, miserable, lonely and poor.
By the time we know the 'cause' of ME, all of the 1950's original baby cohorts will be deceased or too old to feature in 'research'. The accidental recipients of pathogens in the late 1980's who got the mysterious CFS are now aged 35-50 and older. As the average live expectancy is around 75, god knows what it is for very sick long term CFS. Less of course.
Mature aged patients of CFS diagnosis who endure decades of state propaganda, are the people who needed to be studied, the sickest with most secondary 'effects' (e.g arthritis). We could have done back in 1988 and before but the CDC know damn well what is inside the 'CFS' patients, hence it was rapidly created and utilized for 27 years and has just been given a face-lift to display in the showroom to eager customers.
I'm not buying the new update, and want to see the unfortunate marriage of
mitochondria, prions and pathogens published in science journals and replicated by others in the future. Then we're talking specific disease process, not this silly CFS or SEID nonsense which is unspecific.
If the Mitochondrial matrix is attacked by an autoimmune process attacking a pathogen that shouldn't be somewhere,
you will be very ill at rest (not just exertion). If you exert you will harm the mitochondria, and be annihilated due to then suffering an increase in immune symptoms/inflammation and depleted ATP to the point you can barely breathe to speak (what severe ME CFS sufferers report). This inflammatory response mimics what happens in relapse in other autoimmune diseases such as Lupus, when they over exert, but in ME, the biological mechanisms are obviously novel and not understood yet. Yet.
ME must be an autoimmune mitochondrial disease of some sort. Thus it would definitely involve pain, and likely involve neuroinflammation -
what the SEID doesn't focus on.
For the IOM to call reduced CCC CFS + no pain + no inflammation a more appropriate version of ME/CFS (Via SEID), is disingenuous and scientifically false. However, owners of 'fatigue clinics' will love the SEID concept and have people lining up at the doors to get diagnosed with CFS that came out the closet. The physicians in private fatigue clinic practice, are mostly Americans. The IOM is American. The people on the panel helping to form SEID have their own fatigue clinics. Go figure.
A way to wake up from state induced CFS ME zombification, is to pray to God (as an atheist too) new methods of pathogen detection not requiring lumbar puncture or tissue extraction can be developed to demonstrate that ME is not associated to SEID, but a single cause agent.
The 'shoe' of future scientific disease research is still awaiting the correct ME 'foot' to slot into, even if a Govt allied Big Foot has kicked the shoe out the door, and closed it, it's still their laying in the snow awaiting an owner to revive it.