How does one whose ritual impurity (hadath) is intermittent pray, such that it sometimes occurs immediately after purification, and sometimes does not cease until an hour and a half, or two hours, or more, and sometimes ceases for a period after purification then returns? And what is the ruling on his touching the Qur'an and leading prayer in this state?

The fatwa (definition) we adopt is that whoever continuously emits wind or other impurities, such that he cannot perform prayer with proper ritual purity, or if the period of cessation is irregular, then his ruling is that of one afflicted with perpetual impurity (sahib al-salas). He should perform ablution for each prayer after its time has begun and then pray the obligatory prayer and any subsequent supererogatory prayers. What exits from him thereafter will not harm him. As for his leading others in prayer, there is a difference of opinion among scholars regarding this. Precaution and piety dictate that he should not lead healthy individuals in prayer, in order to avoid the scholarly dispute.