Sorry to hear about your surgery and hope that you have a full recovery. I play hockey 3 -4 times a week and have trouble keeping my weight up. I now drink an Ensure a few times a day and that sure helps me get above 165#. I prefer the vanilla because it tastes like a BK shake. Buy it by the case at Costco or Sams.
Try the Costco brand Kirkland Weight Loss Shake, less expensive than Ensure. I mix it with Soy milk as a shake and it makes me go potty too. I'm just a regular guy.