Diarrheal diseases are a leading cause of morbidity among school-aged children in Cambodia. This cluster-randomized trial evaluated the effectiveness of a school-based handwashing intervention on reducing diarrheal incidence among 1,800 students across 12 primary schools in Kampong Thom Province. Schools were randomized to an intervention group (handwashing education, provision of soap, and handwashing facilities) or control group (standard curriculum). Diarrheal episodes were recorded over six months through daily teacher logs and caregiver reports. Results showed a 35% reduction in diarrheal incidence in intervention schools compared with controls (p < 0.001). Handwashing compliance was higher among younger students and in schools with active teacher engagement. The study demonstrates that structured handwashing programs can significantly improve child health outcomes and reduce preventable disease burden. Scaling up these interventions nationwide could substantially contribute to public health gains in Cambodia and similar low-resource settings.

Keywords:
Handwashing, diarrhea, school health, Cambodia, public health intervention, child health