DS has reflux and is on Zantac. While we saw some improvement, we saw more once we added probiotics. While they can be expensive (we use BioGaia), they seem to help his colic symptoms. Our next step was alimentum, but hopefully we won't have to change formulas!
THIS ... Except we already switched to alimentum when DD was 1 month old. Like you I have a very active almost 17 month old and it is hard. Luckily I went through this with DS so when DD started I knew what the problem was. Give the Zantac and alimentum time to work ... Sometimes it can take a week or two. For sure add the probiotic.