An adequate dosage of oral turns the stools a tarry green color. The nurse advises parent of this normally expected change and inquires about its occurrence on follow-up visits. Absence of the greenish black stool may be a clue to poor administration of iron, either in schedule or in dosage. Vomiting or diarrhea can occur with iron therapy. If the parents report these symptoms, the iron can be given with meals and the dosage reduced and then gradually increased until tolerated.