When my daughter was one month old, we had to begin thickening everything that went into her mouth, due to reflux. We decided to use rice cereal, because it was the cheapest and the easiest to use. Well, long story short, she developed a sensitivity to it. She never was truely allergic to it, but was unable to eat it without profuse vomiting and a terrible stomach ache. We were able to feed her oatmeal instead. Maybe try that... Along the lines of allergies, when she was little, she had many sensitivities. At one point, she couldn't eat dairy, soy, apricots, prunes, rice cereal, bananas, and nuts. She is now 2 years and 3 months old and has grown out of most everything. She can pretty much have all of that stuff, with the exception of drinking milk and eating nuts. We have just chosen to keep her away from nuts until she is three, just to be on the safe side. Try to hang in there for now. It is rough for awhile, but hopefully, if he is sensitive to anything he will grow out of it. Most little ones do.