Do you use seals before applying your stoma bag? If you've got a temporary stoma, then your waste is often quite liquid-like. I've had both the temporary stoma, but now I've got a permanent one, and it's so much easier to look after.
The soreness happened to me early 2024 after my first operation (lower rectal cancer), and I hated it, but got used to it over time. I had a major 10.5-hour operation in January 25 as the cancer was not all captured in the first operation, so I was told the best way to eradicate the alien from up my bottom altogether was to have a full rectum removal. It wasn't what I wanted to hear, but I rejoiced when I saw my fantastic surgeon/consultant early April this year and was told that the biopsy from the remaining rectum he removed had proven it hadn't spread and all remaining 39 lymph nodes were cancer clear.
Good luck in getting the soreness sorted. Seals (ringos/donuts), whatever they call them in different areas, are the best thing to use as you'll not get any liquid breakthrough onto your surrounding skin. It made the world of difference to me. x