Drinking a lot of fluids can be hard on your digestive system.
Often you have to drink a higher volume of fluids than your body can absorb at one time. Your digestive system must work overtime to get rid of the fluids it cannot process. When your body starts to try and get rid of the excess fluids, it can lead to you flushing out many of the nutrients your body need.
Rehydrate via IV Ingredients - Electrolytes and sodium chloride.