Is there special underwear for men who leak after prostate surgery?

UW: "depends" are fairly commonly used.

Garment Guards: As a matter of fact, there are several products available from simple inserts into regular briefs, to an actual disposable garment worn like briefs. It depends on the degree of the problem and your personal preference. You certainly don't have to worry about embarrassing situations with either method and you should obtain and try several types before calling quits since they all fit differently.