I think you need to ask your neurologist that question. Or maybe if there is a DMD clinic, the nurses there might be the best people to understand about DMDs and potential problems.
Chances are a drug like Tecfidera won’t be ideal as it a) requires that you pack the tablets in with food, either side of the pills, and b) it can give you stomach discomfort.
But there are DMDs which won’t be hard on your stomach, I should think that an injectable might be a better option for you, or maybe an infusion (if you can manage to get one). Have a look at https://www.mstrust.org.uk/about-ms/ms-treatments/ms-decisions-aid If you compare the various methods of ingesting each drug together with potential side effects, youllbe able to see what might cause more of a problem.
Best of luck.