Stunting is a prevalent form of child undernutrition and is associated with lifelong adverse health outcomes and loss of human capital. The Water, Sanitation, and Hygiene (WASH) Benefits (Bangladesh and Kenya) and Sanitation Hygiene Infant Nutrition Efficacy (SHINE; Zimbabwe) trials were conducted to test the independent and combined effects of improved household WASH (improved pit latrine, handwashing station not connected to a water source, point-of-use water chlorination) and improved infant and young child feeding (IYCF, complementary feeding counseling and daily small-quantity lipid nutrient supplement) on child linear growth. Together the trials enrolled >19,000 women during pregnancy and measured >15,000 of their children at 18 months (SHINE) or 24 months (WASH Benefits trials) of age. Throughout the 3 trials, the IYCF intervention increased mean length-for-age Z-score by 0.13-0.26. None of the WASH interventions had any effect on linear growth among any of the study populations. This lack of effect is most likely because the household-level elementary WASH interventions employed in the trials were not effective enough in reducing enteropathogen exposure to facilitate linear growth. Consensus papers of the trials recommend identification and implementation of "transformative WASH" - interventions that radically reduce fecal exposure - to be made available to rural low-income populations.