How long have you been on it? My research is showing more and more that many strains do not survive stomach acids too well. Spore based strains like L. Sporenges and Bacillus Latero Sporus survive and thrive. Used in conjunction with a candida enzyme dissolver like Candex, you can get quite a synergy. I've tried bio k, and many other formulas but have not been successful long term. So in focusing in on this I keep turning up these spore based organisms. Paul Pitchford, author of Healing With WHole Foods also recommends them. I am giving the above mentioned a try and will let you know how it goes. My bowel movements are already much better(3 days)and I am now having 3 movements a day(never achieved before on any other probiotic supplementation including SBOs).
I have been reading seemingly miraculous recoveries with spore based probiotics on IBS and Colitis, etc. in many forums. I thought it was worth a try.