Scord, this is a great site as you can be assured that we have all been through what you're experiencing in your adventures. I'd been diagnosed with cancer, so, my colostomy surgery was over 20 years ago. Every morning since feels like I've won the lottery*!
Throughout the intervening period, I've had multiple "discomforts" but none of any particular import. From time to time, though, I do experience sensations which used to prompt an impending bowel movement. In time, I found these to be "missing limb" related (the person with an amputated arm gets itchiness in the missing hand). In my case, it was a dull pain in what's left of my butt.
You really need to develop a relationship with your ET ("stoma nurse" is sometimes a degrading term). I've had an array of allergy-related issues and at one point, I had an oozing mess under my appliance. My ET was sitting across the bathroom from me and said, "...you've got a yeast infection!" (which was simply treated with a powder).
I've had the dreaded hernia and have gone through four surgeries. The lesson here was to do your research with your medical team: my general surgeon referred me to a minimally invasive surgery group who use arthroscopic approaches to the problems.
* Most of the people around me who'd been with cancer aren't around, and that presents another set of concerns. I dealt with a psychiatrist to help me deal with this issue which is called "survivor's guilt".
Scord, all of this to say, you really need to develop and then sustain a great relationship with your entire medical team (e.g. GP, ET, ostomy supply firm, surgeon, pharmacy, etc.).