What electrolyte is absorbed along the digestive tract via active transport only?

The electrolyte that is absorbed along the digestive tract via active transport only is sodium (Na+). Sodium absorption primarily occurs in the small intestine and the proximal convoluted tubule of the kidney, where it is actively transported across cell membranes through sodium-potassium ATPase pumps. This mechanism is crucial for maintaining electrolyte balance and fluid homeostasis in the body. Other electrolytes may utilize passive transport or co-transport mechanisms, but sodium specifically relies on active transport.