Actually eating feces and drinking urine are both unsafe. Yes, it is true that urine is sterile but that is only so long as it does not come in contact with the urethra. The urethra has bacteria and once urine comes in contact with it it becomes infected and could cause infection if it penetrates your stomach defenses (i.e acid, enzymes, etc). Similarly feces are laden with bacteria and can result in a serious health hazard if eaten