Hello Little stinker.
My stoma was perfectly formed at first with the hole dead centre. however, with the enlargement of a hernia on one side everything was pushed over and now it exits more from the side.
The output simply needs to be channelled in the right direction, so there might be several solutions to the problem (some of them already mentioned).
I would suggest sending for a sample of the Salts Dermacol stoma collar (you will need to give them the size of your stoma as these things come in different sizes).
Eventually, my own solution was to make my own baseplates with a detachable 90degree bend which guides the output away from the stoma and into the sleeve/bag.
I did find that there were many fewer leaks if I regularly used an adhesive (glue) to stick the devices rather than rely on what the manufacturers put on their baseplates. I did use 7730 but it is now unavailable, so now I'm using 'Probond', which is a medical prosthetic adhesive and is working quite well.
Solving these type problems is often all about experimentation and, what works for one person may not work for another. I have found that a number of resolutions to different stoma problems can come about by way of physical, practical prosthetics of one sort or another. However, this does mean a lot of experimentation and DIY which doesn't always work first time.
From my perspective, going down the surgical route (again) poses too many risks so simple 'gadgetry' is my preferred option.
Maybe, if you try some or all of the suggestions proffered, you can find something that suits your needs.