It wasn't quite what I was expecting. He talks almost entirely about Chronic Fatigue, Fibromyalgia, Interstitial Bowel Disease, Temporomandibular Disease, and Multiple Chemical Sensitivity Syndrome. I still skimmed the book.
He starts out talking about the tests doctors will do to try to determine what's wrong, and then how to get second opinions. He talks about the syndromes/diseases I listed above and how he thinks they work and therefore, where the best relief is. He covers recent and current trials on medications and behavioral therapy for those diseases/syndromes. He finishes up by talking about complementary medicine and examining quackery.
I have fibro, but it was diagnosed by the rheumatologist who insisted that even though the pathology on the bump came back "gouty tophus," it wasn't gout (my hands weren't red and swollen). There's not a lot to do about my fibro because I have other things wrong with me that mean it can't be treated. I didn't get a lot from the book, but it may very well help someone who has an "invisible disease."