I Fell Like Bugs Crawling In My Back And My

I fell like bugs crawling in my back and my liver I could see my right side swolling my liver i'am on metronidazole 325mg due to a bacteria that I don't no how I have it because I did not go outside of the country i'am due for colonoscopy but sumetimes i fell wiggling like worm in my spines coming up what can I do under doctor medication