What side effect should a nurse explain to a child taking oral iron therapy?

When a child is taking oral iron therapy, a common effect of this supplementation is the change in stool color due to the unabsorbed iron being excreted in the feces. Iron can cause the stools to appear greenish-black, a harmless side effect but one that can be alarming if not properly explained. This is particularly important for caregivers and children to understand to avoid unnecessary concern.

While constipation is indeed another potential side effect of iron therapy, the specific focus of the question regarding an effect related to stool color makes the description of greenish-black stool the primary concern. Staining of teeth is more associated with liquid iron preparations rather than oral tablets, and low blood pressure is not typically a direct consequence of iron supplementation but rather can occur in cases of severe toxicity or abrupt changes in iron levels. Therefore, the change in stool color is the most relevant and significant effect to communicate to the child and their caregivers.