Water Pills (aka diuretics). You can buy over the counter ones, but the prescription ones are much more effective. Your doctor will probably prescribe one to you if you tell him what's going on. I have a prescription for Lasix and it works very well --- I'm prone to bloating during that time as well as other times (hot weather, sitting in one place too long, flying in an airplane, yadayada).....bad genes from my mom! 
The pill usually begins to work within 30 minutes, and lasts around 6 hours. During that time you will pee A LOT......maybe twice an hour if your bladder isn't that strong --- I'll go around 5-6 times. They say not to take it before you go to bed because you wake up so frequently, so you'd need to find a time when you'll be near a bathroom (will be difficult a day or two before your wedding!). You will also need to be sure to take some potassium (or eat a banana/drink some OJ) to get back the potassium that you've lost.