How do I prevent constipation when my toddler hates foods that will keep her bowel healthy?

Will she eat applesauce or plums? Maybe if she will not eat the whole fruits put them in the blender and try to create other ways for her to eat the foods (sort of like the deceptively Delicious cookbook). Also if you do not give her many options eventually she will eat more or if you dip the foods in things she likes you might have greater chances of her eating it.