The movement  of Na⁺ and glucose  from the lumen  of the intestine  across  the epithelial  cell to the blood  sets up a dissimilarity  in osmotic  pressure  across  the cell. As per the result, water flows by the cell, across the apical and basolateral membranes by easy diffusion. Therefore the uptake of water needs both Na+ and glucose (or amino acids) to be present in the lumen of the intestine. The incidence of water alone in the lumen of the intestine is much fewer effective. That is the basis of glucose rehydration therapy as a remedy for dehydration; a solution of glucose and salt (NaCl) is administered to the patient.  This is a easy inexpensive  but very extremely  significant  treatment  that  has  saved  the  lives  of a  lot of  infants  in developing  countries  who  would  have  otherwise  died  of the effects of dehydration, commonly associated with diarrhea.