Amoxicillin / clavulanate
"I was prescribe this medicine for sinus infection.  I thought I had taken it before, but maybe not.  I started it on a Wednesday evening with the first dose to be taken every 12 hours.  I believe it was the next day I started feeling nauseated after taking it.  Saturday I was headed out, so grabbed my pills so I could take them after eating something.  I got so nauseated I thought I would not make it back home, just a really bad ill feeling.  By Friday evening I had diarrhea that has last into Sunday.  I think I'm done taking this and will call the doctor tomorrow for something else because I also have a cough and the two don't mix very well."