The effect of young children's faeces disposal practices on child growth: evidence from 34 countries.

Objective: To characterize the relationship between child faeces disposal and child growth in low- and middle-income countries.

Methods: We analysed caregiver responses and anthropometric data from Demographic and Health Surveys (2005-2014) for 202 614 children under five and 82 949 children under two to examine the association between child faeces disposal and child growth.

Results: Child faeces disposal in an improved toilet was associated with reduced stunting for children under five [adjusted prevalence ratio (aPR) = 0.90, 95% confidence interval (CI) 0.89-0.92] and a 0.12 increase in height-for-age z-score (HAZ; 95% CI: 0.10-0.15) among all households. Among households with improved sanitation access, practicing improved child faeces disposal was still associated with a decrease in stunting (aPR = 0.94, 95% CI: 0.91-0.96) and a 0.09 increase in HAZ (95% CI: 0.06-0.13). Improved child faeces disposal was also associated with reductions in underweight and wasting, and an increase in weight-for-age z-score (WAZ), but not an increase in weight-for-height z-score (WHZ). Community coverage level of improved child faeces disposal was also associated with stunting, with 75-100% coverage associated with the greatest reduction in stunting. Child faeces disposal in an unimproved toilet was associated with reductions in underweight and wasting, but not stunting.

Conclusions: Improved child faeces disposal practices could achieve greater reductions in child undernutrition than improving toilet access alone. Additionally, the common classification of child faeces disposal as 'safe' regardless of the type of toilet used for disposal may underestimate the benefits of disposal in an improved toilet and overestimate the benefits of disposal in an unimproved toilet.