Dumping?

My Hubby and I are going in for consult to have a GBP. He and I have made a list of questions for the doctor, that we meet up with in a couple days. This Dumping topic is a huge question. Ok, dumping happens from the body not being able to process sugars and excess fat. Does this dumping happen in the beginning, shortly after surgery, for a little while, for the 1st year or so? or, does this happen for the rest of our life? Does this mean that we can no longer ever have a spoon of ice cream and a bite of cake, ever?

So many questions. I also have a question about BM's. I read that some people get diarrhea, is it controllable? Is this an uncontrollable out of the blue, no time to wait type thing?