Within days, we noticed a significant difference in our baby. Our 6 week old was suffering from reflux and my breastmilk caused him discomfort every time he ate. I was on a restricted diet to try to combat his issues, but it wasn't enough. We saw a difference almost immediately once starting this probiotic. He started sleeping better due to not waking up in pain, reflux is no longer an issue (still on zantac per doctor's recommendation, but it works better now), I'm no longer on a restricted diet and the poopy diapers/diarrhea has significantly decreased. Overall, this product is amazing. Very expensive, unfortunately...but worth it.