Calcium polystyrene sulfonate is primarily used in medical treatments to manage high levels of potassium in the blood, a condition known as hyperkalemia. It works by binding to potassium in the digestive tract, particularly in the colon, and facilitating its excretion through the stool. This helps to lower potassium levels in the body, reducing the risk of complications such as heart arrhythmias or muscle weakness. It is often prescribed for patients with chronic kidney disease or those on medications that can elevate potassium levels. The compound is typically administered orally or as a rectal enema, depending on the patient's condition and needs. Its effectiveness and safety make it a key therapeutic option for managing hyperkalemia in clinical settings.