What is the ruling on one who experiences post-urination dripping that continues for a period of time, and is it permissible for him to delay prayer or not attend congregational prayer? And what is the ruling on his prayer if he feels something has descended but finds no drop, or finds only a slight one? And should he build upon his purity when he wakes up, or take precautions?

It is not permissible to delay the prayer beyond its prescribed time. For someone who experiences drops of urine after relieving himself for an hour or half an hour, he must wait for the discharge to stop, then perform istinja (cleansing) and pray. He is not considered to have سلس (incontinence) as long as he can find a time to pray with proper purification. If he is incontinent, then he must perform ablution after the prayer time begins and pray in his condition if he cannot find time for proper purification. If he doubts that something has exited after the prayer, he is not required to repeat it, because the event (of impurity) is attributed to the most recent time.