Good grief! I drink 2-3 diet sodas every day, but always watered down a bit over lots of ice. It makes me burp a lot, but I don't mind. I'm almost nine months out and eat or drink pretty much anything I want, just can't eat or drink very much of it, which is perfect for me because I'm on medication (anti-depressants) which cause a lot of head hunger that no amount of self-control can overcome. So when I crave a donut, or popcorn, or a diet soda, or nachos or whatever, I just go for it, because i literally cannot say no. Only thing I can't handle is pasta, it makes me too full too fast and I end up eating too much and then throwing up, so I pretty much stay away from that. I should say I'm at goal and maintaining well, actually still losing at a rate of about one pound a month, so like I said, I'm eating what I want and usually as much of it as I can and am still alive and kicking and my stomach has not expanded, so my advice to the OP would be wait for your doctor to confirm you've fully healed and are ready for regular food, and then try a couple of sips of your diet coke watered down a bit over ice, see how it goes.