Technology is making possible new approaches to overcome old public health challenges. Cellular networks are now ubiquitous in resource-poor settings and offer new opportunities for high-yield interventions for both chronic and acute diseases. We are specifically interested in developing mHealth solutions for diarrheal disease for two reasons. The first reason is that diarrheal disease globally remains the second leading cause of death for children less than 5 years of age. Barriers to combat this problem include poor adherence to guidelines for rehydrating children and outbreaks often outpace current epidemiological tools. The second reason is that diarrheal diseases in a setting like Bangladesh, including cholera outbreaks, are a model system to develop and test mHealth solutions that can be coopted for more complex chronic and acute diseases. In partnership with the Ministry of Health and Family Welfare in Bangladesh, our specific aim is to deploy our mHealth platform in a cluster randomized controlled trial (CRT) to evaluate the impact of automated decision-support on clinical guideline adherence, provider uptake and capacity to detect diarrheal disease outbreaks. The subaims are to (i) determine if the platform improves adherence to rehydration guidelines for children with severe dehydration from diarrheal disease, with a sub-analysis for children with severe malnutrition, (ii) assess provider uptake by comparing the number of diarrheal case reports captured by the mobile platform to the existing reporting system, and (iii) validate diarrheal outbreak clusters detected by the mobile platform by comparison to the existing reporting system. This project is significant because it may reveal an unanticipated gate-way to a larger clinical and basic science research agenda. This may include opportunities to provide real-time decision-support for the prudent use of antibiotics, monitor vaccine efficacy at the level of individuals or communities, and to make important discoveries on the microbiology and pathophysiology of diarrheal diseases.