I have a problem with the poll. Technically, i have fibromyalgia as well as ME/CFS, which is to say that I meet the criteria for both syndromes. However, I consider the symptoms cluster called "fibromyalgia" to be a subset of my ME/CFS symptoms, not a separate "fatiguing" illness. That is to say, the "fatigue" is one symptom, pain is another, along with other things like new onset allergies (none prior to ME/CFS onset), PEM, and others. So, I wouldn't say I have CFS AND FMS, but rather that part of my ME/CFS syndrome is widespread musculoskeletal pain. On the other hand, if I had, say, sleep apnea (definitely a "fatiguing" illness), I would not consider that to be a subset of the ME symptoms, because it is not a definitive part of the syndrome, while widespread pain is part of some diagnostic criteria for diagnosing ME/CFS. I hope I'm explaining this cogently enough!