That's right - size doesn't matter. If it's located in a sensitive area, you're going to feel it. Let's hope in 10 days you feel better. (I've never heard of gastric pacemaker, just the regular pacemaker for the heart. I'll have to look it up and learn something new.)
Just because it is small does not mean that it does not cause discomfort. Hopefully the meds she is putting you on will work. Surgery is never fun, but if you can go the easy route, that would be better. Good luck, and keep us posted.
Kasie