Is it permissible to pray while a drop of urine continues to fall after purification (istinja'), knowing that the condition is chronic according to the doctor's diagnosis, and that it was mentioned in Imam Al-Nawawi's book of fatwas, "Al-Majmu'," that this condition prevents prayer unless one purifies himself?

If one or two drops of urine exit a worshipper and it is difficult for him to wait, then he must purify himself from it if he is certain or reasonably sure of its exit, because it nullifies purification and contaminates the garment, and prayer is not valid until after it is purified. However, if it is urinary incontinence that exits continuously and it is difficult to guard against, its ruling has been clarified in Fatwa no. 34499.