To evaluate the efficacy of a hypo-osmolar and a standard (World Health Organization) oral rehydration salt (ORS) solution in persistent diarrhoea, a randomized controlled clinical trial was conducted in 55 children. After a 1-day observation period the children were assigned to one of three solutions: standard ORS (WHO-ORS) (osmolality 311 mosmol/1), hypo-osmolar ORS containing L-alanine and glucose (osmolality 255 mosmol/1) and iv polyelectrolyte solutions (osmolality 293 mosmol/1) for ongoing replacement of stool loss for the next 4 days. Excellent acceptability of ORS (101-160 ml/kg body weight/day) by the children was observed. There were no significant differences in the total intake of solutions and food, and frequency of stools among the groups Stool outputs were significantly less in infants receiving hypo-osmolar ORS than in those receiving WHO-ORS for 0-24h (p= 0.04), 0-48h (p= 0.01), 0-72h (p= 0.04) and 0-96h (p= 0.03). The results indicate a sufficient scope of ORS practice in persistent diarrhoea. Furthermore, we found that a hypo-osmolar ORS containing L-alanine and glucose is as efficacious as an iv solution and more effective than WHO-ORS for replacement of ongoing stool loss in persistent diarrhoea. Alanine-glucose ORS, hypo-osmolar solution, oral rehydration solution, persistent diarrhoea