Wasn't common for my husband.  

Mouth ulcers (aphthous stomatitis) are much more common in Crohn's than UC, though there are some different mouth sores that can crop up in UC. For some folks they can be used to diagnose or monitor Crohn's. I used to get them when my IBD was acting up. I don't know what these new things on your tongue might be , though. Here's an article that's probably more technical than you were hoping for: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2657699/

I get tongue ulcers about once a year (post J-pouch).  Never had them pre J-pouch.

About a week before I first starting getting my first UC symptoms, I got horrible ulcers all over my mouth, throat, and tongue. I always figured it had something to do with the onset of UC. Interestingly, I never got them again. Also, I was in St. Thomas at the time, which always made me wonder if I was exposed to something unusual there to bring all of this on.

Before I was diagnosed I suffered from really my mouth ulcers. They were mainly just on my tongue and I would have as many as 9 or 10 at once. I was in high school at the time and it made talking, eating, brushing my teeth, etc a very painful experience. Since I got my colon removed two years ago I have only had the tongue ulcers twice and both times it was just one and they were small. I know that mouth ulcer are more common in crohns patients than in UC patients but can occur in both. However I just received my j pouch and am not fimiliar with whether mouth ulcers r common or a sign of a problem. I hope that the tongue ulcers don't become a regular problem for you. I know how much they can hurt. 

I was diagnosed with UC in my early 20's. Throughout my teenage years I always had mouth ulcers and continued to  have them all the time until I was 35 when I had my colon removed. I had an ileostomy for the following 15 years (although I had terrible problems with it!!) and guess what.... no mouth ulcers!! I had a Jpouch formed in 2015 and since take down in August 2015 I have continually had mouth ulcers.

i had a ton of mouth ulcers pre diagnosis of UC. they were really painful and big and i had a lot of them at one time. after treatment i have not had them again, except the odd tongue one as you say but absolutely nothing like it was before the onset of the UC thankfully. i do believe they were part of the onset of the illness.