Need advice on COLIC remedies? Any recommendations?

I need a remedy. My boy has colic. Diagnosed by doctor. He takes infant Zantac every 12 hours and it lessened the problem but he still has the problem in the evening and late night hours. I tried Gas X but it doesn't seem to make a big difference. He drinks Nuetramigen formula which is basically the Alimentum. I'd like the best advice as to what to choose. Might have to take a trip to a CVS or Walgreens for now and grab what they might have there for this evening. Thanks