Bodily issues upon changing diet?

Well I am 21 years old and am trying to lose some weight. (6-1 and 218 lbs) For the last two days now I have gone cold turkey with no cola, junk food, fast food, etc., started working out and drinking plenty of water and eating healthy. My body, however, is reacting weird in my opinion. My stomach has been upset and I have been having diarrhea as well. Is this just a normal reaction of my system flushing out the bad stuff?