there is some usage in both with reguards to crafting since feces can lead to frag mines and urine leads to stun bombs and so on
but theres specifically a gameplay consequence of having urine enabled in that it limits your potion usage since it will cause urinate events if you drink too much
Also theres an event that requires urine enabled to get the resource to start the event in that being the dicc the impaler battle skip event which requires you to collect a jar of urine from yourself to give to orkind slayer