IMHO 'fibro' is the new kid on the block, used instead of 'ideopathic' when they can't figure out what's really going on- or are too lazy or inept to find out. Better to have a dx of something, rather than tell the patient
"I don't know what it is"
Since there is no chemical or blood test for it- it is all subjective, detective work- so there is no definitive way to diagnose for it. Can't have a lab report come back with 'fibro' on it.
Its the new 'catch-all' dx.