The Bristol Stool Chart (BSC) is a picture-based scale originally created to track symptoms of Irritable Bowel Syndrome in English patients. OneVillage Partners adapted this tool to track diarrhea prevalence in communities that implement Water, Sanitation, and Hygiene (WASH) projects in rural Sierra Leone. The picture-based tool is accessible to almost all community members and allows them to self-select their last stool type from a group of seven pictures. OneVillage Partners has found an average 69% decrease in diarrhea prevalence from baseline (before WASH project implementation) to endline (one year after WASH project completion). All five communities surveyed built latrine structures with handwashing stations complemented by household education on sanitation and hygienic practices. The repurposing of the BSC is an example of using participatory evaluation methodologies that are engaging and meaningful to program participants to gather evidence.