We had DS on Gentlease first as a supplement to breast milk, than completely after my supply tanked. He was a gassy, spitting up, poop machine. Today in desperation I switched him over to Similac Sensitive. Within 1 bottle I saw improvements, and now after 2-3 bottles it's like we have a different baby. His stomach is no longer gurgling at each feeding, he is burping a good bit still, but at least he is no longer covering me in spit up after each burping. Hooray for finding a good fit for him!