Help! Why Is My Child’s Poop Like Sand? | WonderBaby.org www.wonderbaby.org/articles/poop-like-sandPrivate View Many illnesses, both chronic and acute, cause changes in bowel movements. Besides being uncomfortable, gastrointestinal problems can cause your child to miss out on essential nutrients, become dehydrated, and in severe cases, cause growth and immune system problems. If your child has poop like sand, you may need to adjust their diet or speak to ...