Final answer:
Patients with Crohn's disease should be monitored for calcium, phosphorus, magnesium, and iron status when experiencing diarrhea.
Step-by-step explanation:
Patients with Crohn's disease should be monitored for calcium and phosphorus status when experiencing diarrhea. Diarrhea can lead to malabsorption of these minerals, which can disrupt the body's electrolyte balance. In addition to calcium and phosphorus, monitoring for other mineral deficiencies such as magnesium and iron is also important as chronic diarrhea can result in nutrient loss.