Hi ! I know exactly what you are talking about! It is def an MS thing. It’s like your brain is taking the ‘piss’ out of you!!
I have had this feeling for a few years and it drives me mad. I would wake up with spasms in my back and although I knew it was just my brain having a laugh i had to go to the loo. This would happen about 6 times a night. It was awfull. The docs put me on diazipam to calm the spasms and it helps. I now have to use a catheter and take Ametrypteline every night. The amitrypteline calms my bladder and helps me sleep. When my MS wants to annoy me the problem comes back, especially if my symptoms come back, so I take a diazipam and go back to sleep. I often end up using the catheter over and over again and end up with infections.
You should ask your MS nurse to refer you to a continence nurse, you never know, maybe all you need is a wee pill to sort it !! I suppose you take lots of pills, so Im sure another one won’t make a difference!!
Please go see the Doctor or the MS nurse.
Keep smiling xxx