Which volume of water is recommended for dissolving a Dioralyte sachet according to the guidance presented?

• A. 200 mL
• B. 100 mL
• C. 250 mL
• D. 150 mL

Answer: (A)

Oral rehydration solutions like Dioralyte are formulated with a precise balance of electrolytes and glucose that is delivered correctly only when dissolved in a specific amount of water. Dissolving the sachet in 200 mL of water achieves the intended concentration, which supports optimal absorption of water and electrolytes through the gut and provides effective rehydration without overloading the intestinal lumen with solutes.

If you use less water, the solution becomes more concentrated, increasing osmolality and potentially causing gastric irritation, slower gastric emptying, or even hypernatremia. If you use more water, the solution becomes more dilute, delivering less electrolyte per dose and reducing the driving force for water absorption, which can slow or lessen the rehydration effect. Therefore, 200 mL is the volume that aligns with the product’s formulation and rehydration mechanism.