Hi Dyna,
Long time no hear...
No, no discomfort now...I did have a non discript feeling quite a few years back that turned out to be a peri-stomal hernia which eventually got fixed.
It could be the muscle (can't really be anything else...there is nothing else around there).
Are you experiencing any loss of continence? Fatigue? Air escaping? Difficulty inserting the tube?
If so there is a problem, if not it may just be a stretched or pulled muscle...do you do any sports? Lifting (beds while vacumming?), pushing or pulling heavy stuff (gardening?)...all of those can lead to muscle strain in the abdomen and around the stoma but if there are no symptoms effecting your pouch I wouldn't worry too much (then again I don't know that much about the BCIR and its anatomy).
Hope that it is nothing
Sharon