I need a sugar free, non carbonated alcoholic beverage. Had gastric byp And can't have sugar or carbonation?

You can buy any non-alcoholic/alcoholic brew, pop the cap, leave it in the fridge to allow the carbonation to dissipate. I think for low sugar avoid dark brews like Guinness...look into Belgian White or Bock or Budweiser perhaps. The problem here is that brew has sugars which the yeast feed on during fermentation. Show around and you might get lucky and find what you are looking for but your quest is going to be difficult. Hope this helps...but you may have to swear off beers and sodas until you recover...