IBS anxiety

I have a “thought loop” that has been playing in my head for years and I have been unable to find a new thought I can believe and get my body to believe. I have Irritable bowel syndrome and have constant anxiety around it any time I leave the house. At this point I am not sure which came first- the symptoms or the anxiety, but regardless they tend to feed off each other and its a vicious cycle. I must always have a bathroom nearby and am very anxious while out of the house that I may have an attack at any moment so I now tend to avoid many outings. I have been to therapy for it and have been told my anxiety is something I will always have and just need to learn how to cope when it arrises.
Just as “stop over drinking” teaches, I would like to not have this struggle every time I leave the house. I would like to overcome it and not have it even be a thought when I leave the house.
I was hoping for some help with a new thought to believe, a bridge thought. I’ve had this same thought for so long now it’s a bad habit I just can’t “think” past.