What is the ruling on the drops that fall from behind when performing istinja' in a modern toilet, and are they considered impure?

A Muslim should not pay attention to the whispers of Satan. The water residue that trickles down after ablution should be disregarded. A Muslim does not abandon the certainty of purity merely due to doubt; that is from the whisperings that must be repelled. It was narrated from the Prophet, peace be upon him: "Not unless he hears a sound or perceives a smell." Things are presumed to remain in their original state until the contrary is certain. A mere feeling of something exiting does not nullify ablution. It is not permissible to leave prayer merely due to doubt, unless one is certain that urine has exited. One must beware of Satan's plots and whispers, and not pay attention to doubt. Instead, one should maintain purity and fight Satan.