Well, I didn't think that there was much pain at all, and the only pain I really did have was from the gas pains. Honestly, I am not big on pain, and this was much less painful than a headache. I lost the weight I was expected to, but that part wasn't too much fun...... Luckily for obese people though, those first several pounds do come off without too much effort. You can do it. You can loose the 13 pounds, knowing that the payoff will be many more tens of pounds, and that the surgery isn't terribly painful......... Infact, I was back to wearing a girdle, and jeans at the end of the first week.
For my program, the liquid diet portion is for two weeks after surgery. I think the liquid diet leaves a lot to be desired flavor wise, but it is neccessary, and not too hard to stick to.
Best of luck to you.