A nurse is teaching a client who has a new prescription for aluminum hydroxide to treat heartburn. The nurse should instruct the client to monitor for and report which of the following adverse reactions?

A. Flatulence: While some antacids may cause mild bloating or gas, flatulence is not a primary adverse effect of aluminum hydroxide and does not usually require monitoring or reporting. B. Constipation: Aluminum hydroxide commonly causes constipation because it slows gastrointestinal motility. Clients should be instructed to report persistent constipation and may need dietary adjustments or stool softeners to manage this side effect. C. Palpitations: Palpitations are not associated with aluminum hydroxide use. Cardiovascular monitoring is generally unnecessary unless other conditions or medications are present. D. Headache: Headaches are not a typical adverse effect of aluminum hydroxide. Monitoring for neurological symptoms is not required with standard antacid therapy.