Sodium, potassium, and chloride are electrolytes. Sodium in combination with carbohydrate (sugar) aids the absorption of water from the intestinal tract into the body and helps to retain fluids in the body to prevent dehydration. Potassium works with sodium to help regulate fluid balance in the body. Chloride helps to maintain the acid-base balance of the body fluids and prevent acidosis. It is important that oral electrolyte solution is properly balanced with the various electrolytes to replace fluid losses and keep the body hydrated.
The carbohydrate in the solution must also be in the proper amount. The carbohydrate and sodium work together to move water out of the intestinal tract and into the body, thus promoting hydration. Too much carbohydrate can cause diarrhea to worsen by moving water from the body into the intestinal tract.
This movement of water, electrolytes and sugar across the intestinal tract and into the body is known as osmosis. Solutions with an osmolality lower than serum make effective oral rehydration solutions. Serum has an osmolality of 310 mOsm/l.
PediaVance® Electrolyte has an osmolality of 270. This is the reason why liquids such as apple juice, carbonated sodas, or sports drinks are not recommended as rehydration solutions for infants and children with diarrhea. Their osmolality is way too high and may worsen the diarrhea.