Diarrheal diseases remain a significant public health concern in urban areas of Lagos, Nigeria, despite ongoing efforts to improve sanitation and hygiene. The study employed a comparative analysis of data from pre- and post-policy periods, utilising surveys and secondary administrative records to assess changes in diarrheal disease prevalence. Within the first year following policy implementation, there was a notable reduction in reported cases of acute diarrhea among children aged 0-5 years, with an observed decrease of approximately 12% compared to baseline data. Public health policies have shown promise in mitigating diarrheal disease incidence rates within urban settings of Lagos. Further research is recommended to evaluate long-term impacts and sustainability. Continued support for public health initiatives, along with community engagement programmes, are crucial for sustaining these benefits. Diarrhea, Public Health Policies, Urban Children, Lagos, Nigeria