Soft, yellow stool, bouts of chronic diarrhea

I had my first child 10 months ago and since then have had soft, yellow stools.  Occasionally bloodstreaked, but I figured it was just hemorroids (hemorrhoids).  I recently had a bout of gastroenteritis, according to my PCP, and since then have had chronic bouts of diarrhea up to 20 times a day.  They last a couple of days, sometimes with fever, then go away.  My stool is always soft and yellow though.  I have a lot of nausea with these episodes and bloating.  I also notice that my back hurts and I am weak and clammy.  What could this be?  It's really impeding my life.