What's the difference between a disease and a disorder?

Is there a difference between a gastrointestinal disease and disorder?

• I'm quite confused. I'm supposed to do a powerpoint presentation for my Clin. Med class and I was assigned gastrointestinal disease in cats, but when I search for it, almost all that comes up are disorders. Am I just over thinking it or is it truely a "disease" and not just a group of disorders?

• Answer:

  A lot of things that used to be called "disease" are now called "disorder". IBD - used to be irritable bowel disease, now it's irritable bowel disorder. FLUTD - feline urinary tract disease, now disorder. I think that disease was once the collective term for all these illnesses, but they are now calling them disorders as they aren't caused by germs or organisms, so that they can be distinguished from a real disease. I guess something like intestinal lymphoma would be considered a disease, but other than that I can't think of anything?