If a person takes a long time to finish urinating due to a disease in the urinary tract, he should not hasten to perform Wudu' (ablution) until he is certain that the flow of urine has completely ceased. Then he should perform Wudu' and Salah. Even if this causes him to miss the congregational Salah, he is excused. Allah (Exalted be He) says:
So keep your duty to Allâh and fear Him as much as you can
However, the person concerned does not come under the same ruling as patients with urinary incontinence, because his urine stops but it takes time until it stops. He should also wash any parts of his clothes or body that are contaminated by urine before performing Salah. It is advised that the person with this problem should start relieving himself at a time early enough to be able to finish urinating and be ready for the congregational Salah.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.