Hi, Fiona . . . I have both anxiety and IBS (anxiety since a teen and IBS for over 20 years). I know how they can bounce off of each other. If you get anxious, it can aggravate your stomach acids to irritate your bowels (I often get diarrhea or sticky stools) and sometimes even cramping. The sensations that you are going through with your digestive tract can make your anxiety worse because it is always in your head that there is something more going on.
My doctors have never done anything for my IBS either as it is considered to be one of the most benign bowel conditions. I am able to control mine by knowing what food ingredients trigger it and avoid those, and if I can keep my anxiety down, I am fine.
Let us know how your doctor appointment goes!
Lindaru