Your doctor is correct that in someone already diagnosed with MS, it wouldn’t be called transverse myelitis anymore.
I don’t mean it’s suddenly changed what it is, but the terminology changes, because transverse myelitis is only usually used of a symptom that occurs in isolation in someone who doesn’t have MS (such a person may or may not go on to develop MS - time might show it to have been their first relapse, or it may never happen again).
Once we have a definite diagnosis of MS, it’s pretty unusual to talk about having transverse myelitis anymore. It’s not exactly wrong, just a bit redundant - like diagnosing “cough” when the person is already known to have lung cancer. It certainly might be true they have a cough, but it’s ignoring the wider context - and, without further detail, potentially rather misleading.
So with transverse myelitis - if you do have it, then essentially, as a diagnosed person, it wouldn’t normally be called that, and you’d be described instead as having an MS relapse, which gives a more realistic picture of the circumstances.
I have rather the opposite with my doctor - if I go with back pain, she asks me if I think I’m having a relapse. If the doctor doesn’t know, I’m not sure I do, but so far, my reply has always been no, on the basis that it doesn’t seem to be in conjunction with any other symptoms, and I’m pretty confident it’s just mechanical - i.e. an injury. I am more prone to injuries due to poor muscle strength, so I do think my back pain is related to MS, but I don’t think it’s a new relapse every time. I think my gippy muscles have just failed to support my back properly, and I’ve gone and hurt it.
Don’t write of the cocodamol without trying. Without a bit of trial and error, it can be quite hard to determine the exact nature of a pain, and hence the best treatment. When my back goes really badly, it ONLY responds to a heavy regime of conventional painkillers - chiefly codeine, but paracetamol and ibuprofen alternated to the extent allowed.
It DOESN’T respond to neuropathic painkillers (like Gabapentin), and that’s how I can be pretty confident it’s an ordinary musculo-skeletal problem, and not a relapse. I’m sure if it was strictly nerve pain, codeine shouldn’t touch it, and something like gabapentin should. The proof of what kind of pain it is is sometimes what it responds to.
I’ve had similar with my feet. Despite a conviction it wasn’t nerve pain, I eventually yielded to persuasion from my neuro - who thought it was - and agreed to try a course of gabapentin. As expected, it did diddly squat, and I’m back on codeine - which works. So, as far as I’m concerned, point proved - it’s NOT nerve pain.
But it can be very hard to tell without having a dabble, and finding out what works.