Must one make up the Dhuhr, Asr, and Maghrib prayers if the worshipper felt something exit during the prayer and confirmed it to be wady after finishing, knowing that he had held his urine due to the unavailability of a suitable place to relieve himself?

Wadi (prostatic fluid) invalidates ablution by consensus. It is a thick, white fluid that is discharged after urination or when lifting something heavy. Its ruling is the same as that of urine regarding impurity and invalidating ablution. It is obligatory to wash the area it comes from and any clothes it soils. If it is discharged after the prayer, or if its discharge during the prayer is not certain, then the prayer is not invalidated. The default is that nothing has been discharged.