What is the ruling on the prayer of one who has been afflicted with a severe illness that has rendered him immobile, and who experiences urinary incontinence (or seminal or pre-seminal discharge) during his sleep, and cannot distinguish between them, and who previously suffered from urine drops escaping after urination, and sometimes this occurs after ablution or after hours? What should he do?

If your feeling of semen, urine, or prostatic fluid exiting is merely a doubt, then you are not required to investigate. It is sufficient for you to build upon the original principle, which is that nothing has exited. However, if the exit of semen is confirmed due to illness and without pleasure, it does not necessitate ghusl (ritual bath); wudu (ablution) suffices. If the discharge is prostatic fluid or urine, both are impure and invalidate wudu. If the discharge of any of these fluids reaches the extent of incontinence (sals), then you must perform wudu for each prayer after its time has begun. The subsequent soiling of clothes does not harm you, and there is no need to re-tighten or re-bandage for each prayer unless there is negligence.