Hi stimpy
Welcome to NeuroTalk

.
A few thoughts:
Prednisone and, to lesser extent, methotrexate are often used in management of ulcerative colitis. If they stop working there is another class of medications which you could discuss with your doctor - they block the action of a protein called TNF which is important in the inflammatory response - infliximab (trade name Remicade) and adalimumab (trade name Humira) are examples - there are others.
I think that getting checked out by a neurologist is a good plan - I hope that you get some helpful answers.
All the best.