Also, be aware that stuff like brown rice syrup has a variety of different sugars in it, including disaccharides such as maltose. One thing you could try is some dextrose (corn based monosaccharide) versus some rilose (a rice based monosaccharide from the site I listed in my last post). If you are fine on both of those then it is probably a disaccharide intolerance. I don't like HFCS either (for many reasons).