Solid Chocolate is hard to digest, and almost always made with milk products and high in fat.
You can still eat "chocolate" desserts that you make though, especially one's in Heather's Eating for IBS book. Cocoa powder is safe, the problem is with the cocoa butter and other milk products that are used to make solid chocolate. When you bake, you can use cocoa powder.
HFCS stands for High Fructose Corn Syrup. If you are confused about more abbreviations there is a nice list here . I see HFCS isn't not on there, but maybe someone can add it since we use it so often.
-------------------- ~~~Pain is inevitable. Suffering is optional.~~~