My baby boy had the same problem. My dr. suggested 3 things, soy formula, 1-2ounces of apple juice and putting a qtip with vaseline on it and putting it up his little rear. I gave him apple juice and did the qtip trick and it worked but of course check with your dr. I think my baby was a little older like 1-2 months old. Your baby might be too young for the apple juice??
