7mm is very small, but so is the exit tube. I can't find the diameter at the moment, but let me tell you this: you do NOT want to have it blocked any time - let alone when you're flying.
I had a stone the size of a small chicken egg and it gave me some problems a couple of times but then was asymptomatic for years. Then it got me.
The pain - like a spear shoved in my solar plexus that came out between my shoulder blades - is indescribable, so I won't try.
I had one of the first laparoscopic procedures and walked out of the hospital in 36 hours, and that included taking the bag out as well. Never missed it, despite being a glutton. Back to flying time? Rules is rules, but I felt fine in a week.
As a pilot, I'd like to have been without the gall-bag and appendix over those years.