This document discusses integrated programming to promote child development through improving water, sanitation, hygiene (WASH), nutrition, and early childhood development (ECD). It notes that undernutrition and diarrhea often occur together, negatively impacting nutrient absorption. Improving WASH behaviors like handwashing can significantly reduce diarrhea prevalence. Environmental enteropathy, caused by too many gut microbes and toxins, also impairs nutrient absorption. The period from 6 months to 3 years sees the most rapid growth faltering. Integrating nutrition and ECD interventions has strong synergistic effects on child development outcomes. While integration offers advantages like efficiency, it also presents challenges around coordination, measurement, and staff workload that need addressing.