Because people in developing countries are frequently forced to use contaminated water in preparing the oral rehydration solutions (ORS) used to combat the effects of diarrhea, the question has been raised whether and how ORS's can be disinfected. This report summarizes the results of a meeting held by A.I.D. health personnel with consultants to discuss this question. Studies have documented a significant presence of Escherichia coli in ORS's of varying water quality. It is not known, however, whether drinking contaminated ORS results in reinfection or in prolongation of the diarrheal episode or at what point the ORS usually becomes contaminated. If it is assumed that contamination comes from the water itself, several options for disinfection exist: adding a bactericidal agent to home water storage vessels, boiling the water, exposing the mixed ORS to the sun's ultraviolet rays, or adding a disinfectant to ORS packages. In reference to the latter, the consultants suggested that further research be undertaken to answer such questions as what disinfectants would: have a high bactericidal/viricidal activity; be relatively inert with regard to the ORS components; not decrease the shelf-life of ORS packages; be palatable; be low cost; be chemically inert with metal ions often found in untreated water; not adversely affect the inflamed gut. It was also asked whether adding a disinfectant to ORS packages might not spur a movement to add supplemental vitamins, minerals, and proteins and whether the costs of adding disinfectants might not be better used, e.g., to improve public knowledge of ORS or to help countries produce their own ORS packages. After discussions on alternatives to water purification strategy, e.g., reducing the size of the ORS package, and on the basic relation between drinking water and health, the meeting ended with a general agreement that, pending the results of further research, disinfectants should not be included in ORS packages at this time. Lists of meeting participants and of further research questions are attached, along with a report on the effectiveness of disinfecting ORS by sunlight and a brief description of methods of disinfecting ORS.