To answer the original question, I've had a (possible) slipppage a couple of months ago. My only symptoms were light to medium pain in the gut for several hours after a solid meal and vomiting (real vomit, not PB) a couple of times.
One Saturday morning, after my fourth (and worse) vomit episode the night before, I had trouble keeping yogurt down, so I decided to stick to liquids for the weekend and call my doctor on Monday.
We then did a complete unfill and I spent 2 weeks on liquids and mushy food.
We did a fluoro 2 weeks later, which didn't show anything (that's what I mean by "possible slippage" - we think it was a slippage that healed itself with the unfill and gentle food).
I know I got off lightly, mine wasn't a traumatic experience at all. I just went back today for my first fill after all this.