Question about my stool maybe TMI for some but?

As of three days ago my stool has come out in small pieces at a time. Its normal colored. And I read that this can be because of my diet, due to a busy scedchule Ive been eating: -junk food (chips, candy, cookies, fast food) and soda for the past week straight pretty much. Im chugging water like crazy right now (but really Ive barely taken in water since last week sometime now), so is this the reason ? JW. Thanks.