bacterial infection
"I took this medicine for 5 days, and then I decided it was not worth the suffering.  The dentist wasn't even sure I needed it, but prescribed it anyway.  I stopped taking it because of extreme pain on my left side, right below my breast. It didn't feel like any gas I've ever had, but I guess it was some type of intestinal pain.  I was also having frequent, urgent bowel movements though not diarrhea as they warn about.  Now five days without the meds, and I'm still nauseous, especially after bowel movements. I'm bloated, gassy, and just generally feel awful.  What a mistake it was to trust my dentist on this one!"