TMI-NO PIC diarrhea?

This is my second pregnancy and with my first I never had contractions that I felt prior to my pitocin induced contractions. This time around I think I do. Yesterday I started getting cramping that was coming every 10 minutes for two hours and then it vanished. Today I got the same cramping occasionally and then again the same tonight. My question is how come every time I get these contraction/cramp things why do I have diarrhea? It's the most annoying/bizarre thing ever.