Anxiety/stress
can be at the root of so many things you would be amazed. On the flipside anxiety can also be
blamed for things that doc's can't figure out, I don't see why from the symptoms you listed your doc would have ordered an upper and lower GI- for muscle and joint pain/the jolt feeling you mentioned??? Were any other tests, like CT, X-rays, done?
I do get weird feelings like that
but I'm diabetic and the shock like feelings are usually in my feet/knees/ankles, and up my legs.
Feel better

becca