I had a total colon removal and small bowel mass removed with resection. I have gained a ton of weight post these surgeries. I don t feel well enough to exerise so I know lack of movement is a cause, but I don t eat very much. I have symptoms of hypothyroid , (been on many depression weight gaining drugs), been told via testing that I am malnutrioned and vitiams just come back out the same form they went in. I am very tired all the time. I had a test that showed I am dumping my fat intake and not processing it. I had my surgeries at Mayo Clinic and my Primary Doc is good. But this weight gain was like 8-10 lbs a month and no one me knew what to do to stop it. It has stopped now but I am 5 3 and 225 where I was under 160. I have a complex case but there has to be something going on. My doctor just perscribed Metformin. ( maybe I can t eat anything that turns to surgar)...