Evaluation of the effects of varying solute content on the efficacy of oral rehydration solutions in a rat model of secretory diarrhoea.

A series of in vivo steady-state perfusion studies in cholera toxin-induced secreting rat intestine were carried out to investigate net water, sodium, and potassium absorption and water influx and efflux from a range of oral rehydration solutions (ORSs) in which the glucose content had been partially replaced by amino acids or food supplements and the sodium content had been reduced to 60 mM. The reference solution used was the World Health Organization formula. There was a significant correlation between the osmolality of the ORS and the net water absorption (r = -0.911; p < 0.02). The greatest net water absorption occurred using comminuted chicken- and tapioca-supplemented ORS.