If it's been asked, I didn't see it, but is the discomfort from chafing or pressure?
If it's chafing, in addition to the bike sprecific sorts mentioned, boxer briefs work pretty good also. I think the main consideration is flat seams, and no seams in the immediate area.
If it's pressure adjust the saddle, a lot of discomfort is just because you're not used to it. If that doesn't help try a new one. A saddle is not something that's one size fits all, and not something to purchase on looks, reviews, or because it's a best seller. I for one can't ride for any distance on a 'flat' saddle, it has to have some curve (when viewed from behind). Currently my most comfortable saddle is about the ugliest one you'll ever see. (25+ yr old stained blue ragged suede with lumpy padding) The most uncomfortable ojne I own is the most expensive and nicest looking too. Did 80 miles on that one two weekends ago, and my sit bones were sore for the next three days. (in the summer I do anywhere from 1300 to 1500 miles a month, so it wasn't just distance)
The most comfortable distance saddle I ever owned was one of the old hard plastic BMX saddles, so try out different saddle types and styles.
Ken.