One hundred children, ranging in ages from a month to a year, with acute diarrhea who were treated at home following the basic standard recommendations, were studied. In order to prevent dehydration, half of the children were given oral solution (OS) containing the concentrated official formula in packets (group A), and the remaining half was given a commercially prepared ready-to-use OS (group B). During the treatment period, two house calls were made and the third day the patient was asked to come in for a check-up at the hospital. The clinical and socioeconomic characteristics were similar in both groups. The majority of parents made some reference to the "salty" taste of their OS, while only a few thought it has a sweet taste. In Group B, there were greater numbers of relatives who did not wash their hands before administering the OS and did it through bottles. A reminder was given on suggestive signs of dehydration expected, during the second home visit, although they were few. In both groups the average amount of OS administered was greater than 40 mL/kg/24 hours. The majority of the patients gained weight during the treatment. Four patients showed signs of slight dehydration (three from group A and one from group B). The OS's bacteriologic examination was positive for enteropathogens in 16% of the samples from group A and in 5% from group B. The average time the diarrhea continued was similar for both groups. Sodium concentration ranged from 60 to 120, potassium from 15 to 30 mmol/L, in 85% of those cases in group A and 98% in group B.(ABSTRACT TRUNCATED AT 250 WORDS)