People had to use bowels, or go to the outhouse before,...in the beginning of indoor plumbing ,many contraptions were devised but sanitation was still a problem,john crapper invented the modern water closet ,we use today. It included an interocular trap for sewer gases a nonporous ,porcelain surface , and tank with water feed protection .the greatest reason though was for sanitation . A long list of disease's come from feces, to close to our living enviorment. Including, dysentery, collera ,hepatitis, staff infections,...the black plage was caused by the same.... Hope that helps !