I had Metronidazole after my bowel surgery in 2013. The only side effects I had from it were surreal dreams (which were quite good fun), and a mouth that tasted like it was full of rotting teeth. I also felt a bit nauseous on and off, but that seemed to come and go with the Lactulose I was taking, so I put it down to that. My resting heart rate was elevated for a few weeks after, but I assumed that was the surgery itself.
I was warned to steer well clear of alcohol. (According to Wikipedia, Metronidazole is also used to treat alcoholics, and I remember an episode of Casualty where an alcoholic was admitted after boozing on top of Metronidazole.)