@Betty Boop,
@BruceMC is referring to collections of words which the medical community put together to form acronyms, which in English refers to the resulting letters - so that IBS refers to Irritable Bowel Syndrome, and so on. "TMS" is also an acronym.
We often joke on the forum that many of the acronyms that our members come across represent words which sound like an official diagnosis, but all they really do is describe the symptoms, often followed by the word "Syndrome" or Disorder". IBS is a perfect example. "Irritable Bowel Syndrome" sounds much more serious and official than "Your bowels are easily irritated although we have no idea why and we don't have any effective treatments to significantly reduce or eliminate your symptoms".
In another post you indicated that you already came to this understanding about the term "fibromyalgia" which is just two Latin words which mean "pain in the fibrous muscle tissues". It's meaningless!