well done, treechug -- it's always great to hear a success story that comes at the tail of much trial and error.
mine is much the same. i cured my constipation with lufenuron. kefir probably operates on a very similar level, since it's got friendly yeasts in the grains that are anti-candida. similarly, lufenuron dissolves the outer shell of yeast, although its action is more global, less confined to the colon.
my guess is you're feeling much better in general, as constipation puts a load on the liver, creates anxiety, etc. congrats. :-)