After administering a proton pump inhibitor (PPI), which action should the nurse take to evaluate the effectiveness of the medication?

A. Auscultate for bowel sounds in all quadrants: While assessing bowel sounds can help evaluate gastrointestinal function, it does not assess the effectiveness of a proton pump inhibitor. PPIs primarily work to reduce gastric acid secretion, not to change bowel sounds. B. Measure the client's fluid intake and output: Measuring fluid intake and output is important for general fluid balance but does not specifically assess the effectiveness of a PPI. This action is more relevant to other concerns such as hydration status. C. Ask the client about gastrointestinal pain: The primary indication for PPIs is the treatment of gastrointestinal conditions like acid reflux, ulcers, or GERD. Asking the client about gastrointestinal pain directly assesses the effectiveness of the PPI in reducing symptoms such as heartburn or discomfort. D. Monitor the client's serum electrolyte levels: While electrolyte imbalances can be a concern with prolonged PPI use, monitoring electrolytes is not the immediate method to assess PPI effectiveness. Reduction in gastrointestinal symptoms is a more direct indicator.