Dudelsack 

Hate to get in the middle of a proper flame war......

......if I might: some of the confusion is this: there are differences between diseases, syndromes, and disorders.

Diseases are well-defined entities with either a known etiology or at least a widely agreed upon set of diagnostic criteria.

Syndromes are a group of related signs and symptoms which may or may not share a common etiology.

Fibromyalgia is a syndrome, which means that sufferers may or may not have a common set of causes. Often as medical science progresses, what appears to be "a syndrome" ends up representing a variety of different diseases.

"Bright's Disease" is the classic example.

I believe the FS is likely to represent a variety of different disorders, which is why there is no uniform, standard therapy. But I might be wrong.