Hi tz.maryk and :welcome:
It sounds like wife has hard a hard time of things.
Does she have a definitive diagnosis of UC? Or are they debating whether it is UC or Crohn's?
What medication is she taking, if any?
Both of these types of IBD, Ulcerative Colitis and Crohn's, can cause mouth ulcers (canker sores). They are considered what is called an Extra Intestinal Manifestation of Inflammatory Bowel Disease and appear when someone is flaring (their disease is active).
So the removal of your wife's colon would not have triggered this, it is triggered by disease somewhere in the bowel or it can be caused by some of the vitamin B deficiencies. Not everyone with IBD gets mouth ulcers and if they have had them at some point it doesn't necessarily follow that they will always get them when they flare, just as never having had them before doesn't mean they may show up at some time. As you can see, very unpredictable!
Of course if you can link it to something hot or acidic she has eaten it could be something as simple as that.
I will link you to the Mouth subforum
here, you will find loads of threads about mouth ulcers there.
My own son suffered with mouth ulcers before I realised he had crohn's. At the time I researched thoroughly and ended up putting him on B Complex tablets, that solved the problem and he hasn't had them since, even when flaring quite severely. Some people also use mouth wash that contains hydrogen peroxide.
Any questions you may have, please don't hesitate to ask!
Dusty. xxx