“Normally, chloride ions are excreted into the stomach, where they are bound to hydrogen to form hydrochloric acid. An almost equal amount of sodium ions, bound to carbonate ions, is eliminated in a second step into the intestines via the pancreatic and intestinal secretions. The chloride and sodium ions are later liberated to form sodium chloride which is entirely reabsorbed in the distal portion of the intestinal tract, the colon. The sodium and chloride ions are not simultaneously secreted in the digestive tract. The interval between the excretion of chloride ions into the stomach and of sodium ions into the intestines accounts for the physiological ‘alkaline tide’ associated with digestion.”