So some people asked for information on "Why Alcohol Is Bad" post surgery. (Particularly directly after) Most of it has to do with wound healing. As people have said, your stomach has a large 'wound' in it from the surgery. There are many studies which describe the effect of alcohol, however this is one of my favorites. For those who don't have time to go through it all:
"In summary, acute ethanol exposure can lead to impaired wound healing by impairing the early inflammatory response, inhibiting wound closure, angiogenesis, and collagen production, and altering the protease balance at the wound site.
As mentioned previously, the host response to chronic alcohol exposure appears to be different from that of acute alcohol exposure. Analysis of clinical data indicates that chronic alcohol exposure causes impaired wound healing and enhanced host susceptibility to infections, but the detailed mechanisms that explain this effect need more investigation."
Do what you want to do. We are all big girls and boys here, however know the risks and benefits of all of your actions.