Is the continuous excretion of feces for hours after defecation considered incontinence, and what is the ruling on delaying prayer until the end of its time when one does not know when the excretion will stop or exactly when the prayer time ends?

If stool exits from you, and then stops for a time sufficient for purification and prayer, then you must perform istinja' (washing away impurities), wash whatever has soiled your clothes, protect yourself with a tissue to prevent the spread of impurity, then perform wudu' (ablution) and pray each prayer at its appointed time. There is no harm in delaying the prayer until the end of its time after the impurity has ceased. However, if the emission of impurity is continuous and does not stop, or if its cessation is intermittent such that there isn't enough time for purification and prayer within its prescribed time, then it is treated like sals (incontinence). In this case, you perform wudu' after the time for prayer begins and pray with this wudu' the obligatory prayer and as many supererogatory prayers as you wish until that time expires.