Electric warm-water lavage toilet seats are in wide use as an appliance beneficial for the maintenance of hygiene and the prophylaxis and improvement of conditions such as constipation and hemorrhoids. In this study, we surveyed the bacterial content in the lavage water of warm-water lavage toilet seats, and fecal bacterial contamination of the gluteal and genital regions due to droplet infection from post-defecation lavage, to examine the problems inherent to the use of such lavage units. The presence of viable bacteria in lavage water was confirmed in this survey. Viable bacterial counts in lavage water were 3-times higher in household units compared to units in public facilities, suggesting a correlation with the replenishment of lavage tank water with fresh water containing residual free chlorine.