It's difficult to see why God should be either male or female since, being unborn, omnipotent, etc., It (God) would have no reason to have a gender (which evolved to aid in the perpetuation of genes). Being immortal ,infinite and all-encompassing, It would similarly have no reason to eat or drink, hence no pooing or peeing.
In some Eastern religions, however, God is indeed mortal and ingests and excretes through Its skin.