When I was having surgery, I could hear the lady next to me (she was having lap band too) ask why she had to take off her undewear. And the doctor said becuase if something goes wrong and they have to use the shock things on your heart, your underwear would catch fire! And they wouldn't have time to take them off. I was so scared and nervous but when I heard that it cracked me up! I needed to laugh. But he seemed serious and it makes sense.