I heard a woman speak at a meeting once and while she was at inpatient treatment for her alcoholism, she said said 4 out of the 10 women in her group had all had gastric bypass and began drinking alcoholically when it was physically not possible for them to overeat any longer due to the surgery. It was a substitute addiction formed when their other option of dealing with stress was no longer viable.
This is much more common a problem than people are aware. This lady in particular never had any type of alcohol addiction and barely drank. Prior to this, she never understood why alcoholics continued to drink when it was causing them so many problems. She now understands this phenomena all too well and was unable to quit on her own and chose inpatient for her recovery.