Marty,I'm glad you're getting your stool tested! I believe I read once at the univ of virginia site that bacterial overgrowth can lead to fat malabsorption(as well as carbs), and they explain how fairly thoroughly...if you're interested, I'll search for that article(it's really good).So I guess it could be either. This may be dense, but wouldn't the gallbladder removal mean more bile salts--unregulated release from the liver? That's why the calcium works so well for those with no gallbladder, because it binds up that extra bile?I had the frothy D as well, a couple of times,when I first got PI-IBS & it's, well, sort of disgusting, eh? Marty, what lab are you using for the stool sample test? It's pretty cool to find out what's going on in the colon...esp if you also get the beneficial bacteria levels tested.Hope you share your results!Talissa