bacterial infection
"Oh my! I have experienced bloating, gas and abdominal pain since taking this medicine.  The infection does not seem to be clearing up and I only have one day left of a 7 day course of 500mg twice a day.  I am tired, have insomnia; and will not take this again.  My abdominal pain is extreme! I have been up since 3am and took it this morning; immediately took a bulking laxative after, to put something in my stomach. Will see if this helps!"