I can't remember if I welcomed you, if so, then this will be a double welcome - WELCOME snit228!!
I have only noticed that their stomach gurgles for a a few seconds, I have not listened for it though and have not noticed that it does it for a couple of minutes. So when you say audible, how close are you?
Actually, a bunny's digestive system should always be gurgling - but very very lightly. You should always be able to put your ear to their stomach and listen carefully, and soon you'll hear gurgling. A silent tummy is not good. A LOUD gurgling where you can hear it from nearby is not good, unless they've just been drinking, as I hear them swallowing and a gurgle that follows - the only thing that I haven't noticed is it happening for more than a minute. I am figuring it's normal for some, but I haven't ever been asked this question, so I'll just ask my rabbit expert friends to be sure, or to at least find out, even if it's normal, why it would happen with some and not others.
Out of curiosity, is he a different breed, and is he much larger than your other bunnies?
Anyone else notice this with their bunny?