I think it's important to emphasize Gerwyn's point that there is no evidence that these particular four conditions share a common cause. Therefore, it's not useful to group them.
I think the frustration with CAA that is being expressed here is that the CAA hasn't in the past emphasized the search for a cause above all else. The CAA appears to many of us to be willing to accept the possibility that there is no cause. People with the disease know there is a cause, because many of us got sick over night. Something caused us to get sick. People with ME/CFS are angry that the cause hasn't been found and that the medical profession and the general public assume that, since the cause hasn't been found, there is no cause. If there is no cause, then it must be all in our heads. This has been the logic used to abuse, ignore and marginalize ME/CFS patients for decades now. I'm trying to say this very calmly, because it makes me angry, too, and I don't want to seem like I'm ranting. I think the CAA will have fewer problems with the patient community if the organization keeps in mind at all times that there is a cause or causes; the cause(s) just hasn't been identified for sure yet. Once the cause(s) has been identified it will be possible to develop diagnostic tests and treatments. It may be possible to develop some diagnostic tests and treatments before the cause is definitively established. In fact, this has already been done by some of our best doctors. Unfortunately, they're not definitive tests or treatments because we don't yet have a validated cause. But it will be much easier once the cause(s) is established. I think the CAA needs to put up a big sign its office that says "It's the etiology, stupid". I mean no disrespect by saying this. I'm trying to be helpful. It does no one any good for patients and an advocacy organization to be at odds with one another.
There also needs to be another sign. This one should say "It's the definition, stupid." This sign could come down as soon as the CAA endorses the Canadian Consensus definition. Until we know who we're talking about we won't be able to find the cause. ME/CFS is not a "pain condition". It's ME/CFS. I think it was Dr. Cheney who pointed out that five of the Fukuda criteria involve pain, yet some of his ME/CFS patients don't have pain. I think he would agree that all of his patients have post-exertional malaise. Yet that symptom is not required to meet the Fukuda criteria, as Dr. Jason pointed out in his webinar. Every ME/CFS patient I know has cognitive problems. Most, if not all, have autonomic nervous system problems. And most, if not all, probably have cardiac problems, often undiagnosed. People with vulvodynia don't have these problems--they have vulvodynia. It is disheartening that the CAA doesn't seem to understand these basic concepts.
So, to go back to Gerwyn's point, it isn't useful to discuss "overlapping conditions" that overlap because they have pain in common. They don't have the cardinal symptoms of ME/CFS, post-exertional malaise+cognitive dysfunction+autonomic nervous system dysfunction+cardiac dysfunction, in common. It's unlikely they have a common cause. It's not useful to discuss them together.
The CAA's BioBank has great potential to address the issue of causality. It is critical that it's clear which of the tissues collected come from people who meet the Canadian Consensus definition and which meet Fukuda, and that it's possible to identify what constellation of symptoms each person has.
Please remember: there is a cause. It's just not definitively identified yet.
By the way, I realize this is an oversimplification. There are very annoying political and economic reasons why we don't have a cause. I'm leaving all that out to make a point. Also, I don't have the Canadian Consensus definition or the Fukuda criteria in front of me, and I do have cognitive dysfunction, so I may be leaving something out. It's the concept of a specific cause or causes for a specific constellation of symptoms that I'm trying to convey.