I'm so sorry that you're going through this. I am in the exact same situation. Two previous surgeries for bowel resections and one for adhesions, last one in 2013 and am on low residue diet and severely underweight. I currently have multiple strictures and dilated loops in my intestines and struggle to keep weight. Down to 78 pounds now. I've been drinking Boost Plus chocolate for several years (it's really yummy!) and it contains 360 calories and 14g protein in a 8oz bottle. The key is to find low volume, high calorie and high protein sources. Recently I bought a case of Boost Very High Calorie chocolate and it contains 520 calories and 22g protein per 8oz bottle. I've just started this a few weeks ago and my weight has seemed to level off. I hope you can find some of these ideas helpful!