Open defecation is the practice of defecation without any kind of sanitation system and is generally accepted to lead to health problems such as cholera, dysentery, diarrhoea, jaundice, typhoid, polio and intestinal worms, either by contamination of clean water supplies or by direct handling of excrement.
Globally, more than a billion people (15% of the total population) practice open defecation.
Appropriate technology sanitation systems aim to improve health outcomes by providing interventions that move human excrement away from the household, out of reach of children and to treat it before release into the environment.
For more pages on appropriate technology sanitation systems, see Category:Sanitation
Literature review and discussion
There is good evidence to suggest that almost all forms of sanitation are better than open defecation. A 2010 review paper systematically considered 15 high quality research papers comparing open defecation to various forms of improved sanitation. It found that 13 of the 15 studies showed an improvement in diarrhoeal incidence, and some gave very large reductions.
Stenström  et al conducted a risk assessment of many common components used in WASH systems. They concluded that open defecation represents a high risk of daily infection for users and a high risk of infection to the general community who have to live with it.
- UNICEF/WHO Joint Monitoring Report - 2012 update
- Clasen TF, Bostoen K, Schmidt WP, Boisson S, Fung ICH, Jenkins MW, Scott B, Sugden S, Cairncross S. Interventions to improve disposal of human excreta for preventing diarrhoea. Cochrane Database of Systematic Reviews 2010 Issue 6
- Stenström TA, Seidu R, Ekane N, and Zurbrügg C. Microbial Exposure and Health Assessments in Sanitation Technologies and Systems (2011). EcoSanRes