Unless you're paddling in rough conditions, or really snapping a lot of rolls, there's not much about kayaking that is going to aggravate a disk problem... except for all the sitting.

As a first step, I would take a look at the Stuart McGill back exercises and see if they help. Google is your friend on that one.

Then seat adjustments.

Beyond that, back pain is super-tricky and I'd seek out a medical professional who specializes in it.

: I've got a couple of mildly bulging disks in my lower back. It
: doesn't really hurt while I'm paddling, but sitting in general
: makes it unhappy the following evening. Everybody is different,
: but I'm wondering if anyone else here has that problem and has
: found ways to minimize discomfort that works for them. I do use
: one of those elastic braces and it seems to help. Any other
: ideas.
: Mark