There is a getting used to period in the gut for this live bacteria. I find slowly introducing it creates less initial adverse affects rather than once every day. I also believe the flavor and smell of it is what most babies issues with when trying to take it as opposed to diluting it in a bottle its incredibly concentrated. Otherwise, it helped our little one reduce spit up and keep eczema at bay. Baby was off evivo for a couple weeks and developed eczema and horrible reflux. Just hoping starting again will help to get rid of it again!