Alcohol
I'm one of the other refugees from the other site.
I noticed in this discussion that VS surgery is supposed to remove the pyloric valve. That is not true. It is with bi-pass, but that is why I didn't choose that procedure. Its loss leads to dumping.
I'm not a fan of drinking post surgery. It throws people off their goals. And even in maintenance, it is a source of empty calories (leading to extra pounds which I am now working hard to get off).
I don't think you can make a case that the surgery makes us incapable of having alcoholic beverages, or somehow it now goes straight to the liver. Actually, I think you can make a better case that it goes through our smaller space faster and less alcohol is absorbed in the intestines than in the stomach.
But that said, the danger of transference addiction, difference in tolerance and effect are very real. After looking into this a great deal, I really recommend looking into the Sinclair Method to control drinking. It is good at blocking the reward centers which lead to much of the addiction problem and is far more effective than avoidance only programs for those who drink. I checked with the scientists who did much of the original research on this and it can be used before a problem develops.