I had a sleeve done and what my surgeon said was a large hernia repair. About a year post-op, I got pancreatitis from an errant gall stone and had to have my gallbladder removed. It seems to be quite a common occurrence in people who lose a lot of weight quickly.
Top 3 pieces of advice?? 1. Track your food, your calories. Empty calories go down easy but don't fill you up. Protein first, even now. 2. Measure your portions. I lost my hunger after surgery and it hasn't really come back, but I can still mindlessly eat if I'm bored or anxious. I still measure my food because I know I can be satisfied with less than my eye tells me if I just pile stuff on the plate. 3. Do weight-bearing exercise while you are losing and keep doing it. I lost a tremendous amount of muscle mass and it has taken quite a long time to rebuild the strength I had before surgery. It takes muscle to haul around that excess weight and it's easier to keep it than gain it later.
Good luck with your surgery. I hope you are as happy as I am with the end result/