I haven't have surgery yet and I'm already having a sensitivity to refined sugar. I'm four months into my pre op nutritionist monitored diet. Today I had a piece of my son's birthday cake and it's killing my digestive system. I had one last Friday also and the same thing happened. I've been pretty good following my diet,but have just noticed on days I have problems. Anyone else notice this? Is this an indication that I will have bad dumping after surgery?