I have IBS. Starting in college, on top of the IBS, at least once a year I would end up in the ER due to a week+ of stomach troubles. Tired of reading the ER reports, my gastroenterologist told me he wanted me to start taking Align. I can't say for sure how long they took to "work" or that I noticed a difference in my day-to-day life. What I can say is I have not had another serious "stomach flu" or intestinal infection requiring a trip to the ER and being hooked up to an IV. Align has definitely made my life better. I have been taking it for years. For most effective results, take every day and not just when you're having a flare up of symptoms. Buying Tip: if you belong to Costco or the like, buy your Align there. It is a MUCH better deal, even if you have a coupon for another store and it's not on sale at Costco. I only buy it at Costco because it comes with at least 6 week supply.