This is a link to previous discussions about gut pain and the Big 3. Perhaps you can find some helpful tips among them. I wonder if switching probiotics might help, and/or timing of taking meds?
https://connect.mayoclinic.org/group/mac-bronchiectasis/
I made note of these probiotics some here have used with success. Disclaimer: I have not been on the the med cocktail. Align, Endomune or VSL#3