I Have C-diff But Now My Stools Have Turned Dark

I have C-diff but now my stools have turned dark green almost black.. I had c-diff a month ago and was on antibotics it cleared up but came back two weeks later! My Dr referred me to an infectious disease Dr who cant see me until Sept 17.. I was told to call my primary and get antibotics until they can see me on the 17th. I am concerned about the color of my stools as it was not this color before!