I Just Cut My "hand MRI" Short At The Mayo

I just cut my "hand MRI" short at the Mayo clinic after about 20 minutes. When asked "how I was doing" certain sessions would literally MOVE the inside of my bowels in a wave like motion. Not painful, but would conclude in rhythm to certain pulses, while other sessions...nothing. I'm generally calm by nature and perfectly comfortable w/MRI as I have had a few in the past without this experience. I would have kept going w/the test but it totally freaked me out when the radiologist said she never heard of such a thing in her entire career and told me I was just "nervous" and it's just my "bowels". Am I crazy? Dud I hurt myself with this giant donut?

David.