I have had anxiety for many years from a traumatic childhood. But for as long as I can remember, I've also had what I always called "a weak digestive system with indigestion" every now and then. I now think this is IBS (haven't had it diagnosed). But my problem is that the indigestion/discomfort/stomach spasms CAUSE me anxiety in the moment- until the indigestion passes or I go to the loo. 
I know that anxiety can cause IBS, but can the reverse also happen? It causes me extreme discomfort+ anxiety + panic.