Which patient statement indicates a need for additional instruction about taking oral ferrous sulfate?

The statement indicating a need for additional instruction about taking oral ferrous sulfate is the one about notifying the health care provider if stools turn black. This reaction is a common and expected side effect of iron supplementation, particularly with ferrous sulfate. The iron interacts with the digestive system and can lead to the formation of blackened stools, which is often harmless and indicates that the iron is being absorbed effectively.

The other statements reflect correct understanding and practices related to taking iron supplements. Increasing fluid and fiber intake is recommended because iron can cause gastrointestinal side effects like constipation. Taking iron with orange juice enhances absorption due to the vitamin C content, which is beneficial. Lastly, using a stool softener is a suitable approach if constipation occurs, providing a proactive measure to manage this common side effect.

In summary, the advice regarding black stools should not cause concern, and understanding this aspect is crucial for patients to manage their treatment without unnecessary worry.