Just a few years back, Le Cruset pans all had that un enameled top to the pot and bottom of the lid. I have several....and if you let them sit in water they will rust....and I suppose, eventually the rust will cause the enamel to pop....but it's never gotten that bad.
Clean those rims with Barkeepers Friend and make sure they are dry before you put the lid on the pot. I store my lids upside down on the pot, cushioned with a square of bubble wrap.
If a little rust will stain your counters, what do you do about a drop of red wine or grape juice, beet juice or even mustard? Surely the counter has some sort of a sealer on it.
Linda C

Thanks,Linda. I worry about my countertops b/c they are new. We haven't even moved in yet so it's sort of like dreading the first ding on a new car. It will happen someday but I don't want to do something dumb. I'm going to try the BKF in hopes that I'll avoid a problem. If the rust doesn't come off I'll donate the pot to Goodwill or Salvation Armmy b/c I'm not going to take any chances.

The rust should come off with a bit of scrubbing. To keep it from happening again, after the pot is dried on the stovetop and cooled a bit, dip a finger in a bit of oil and run it over the rim to coat. Or do it on a hot pot with a silicone brush to season the rim. If you're worried about your counters just get one of those silicone mats to put under it. Don't leave it upside down to dry on the counter. That will leave rings.