My child has had bowel issues for almost 1 yr. black tar looking stool that is thick. She doubles over in pain. When it does come out its not much and it has sandy like particles in it. Not pinworm. She tries to hold it in. The smell is almost a burnt smell if that makes any sense. I've tried miralax, high fiber, fruit, even a gluten free diet. I made an appt w/ gastro for this week. Is this the route to take?