Can lack of exercise and healthy diet cause difficult bowel movements even if stools are normal and not hardened? normal stools but difficult passing?

Fiber & water.: By "lack of...healthy diet", we usually would refer to the lack of fiber-containing foods and enough daily water intake. Both of these are important for the easy passage of normal stools. Lack of such can lead to stools that are more solid than they should be and therefore more difficult to pass. Believe it or not, a "normal" stool is 75% water so adequate water intake is important for this.