I've been where you are. I was obese had UC and at times c.diff. I've battled it with my j-pouch too. First of all you need to get rid of the c.diff. If I ever get again I am pushing for a fecal transplant. Depending on were you live it might be a problem. Please PM me or do a search here on the subject and it will come up with several good topics and recent posts. I have it planned ahead because I suffered from it and cuffitis in my j-pouch at the same time. It was worse than when I had it with UC. It would clear up a bit and then come back so I was on and off Flagyl for almost a year. Fecal transplants were rare at that time. Cipro gave me my first c.diff infection while I still had my colon so I can't take it ever again. I mention this in case you've been given it.
These surgeries were a weight loss plan for me. I lost around 80 pounds in a year after my surgeries. I've put some of it back on but am still down 50 lbs. My metabolism is screwed up because of my hypothyroidism disease. I was 90 pounds overweight at 5'8 before the surgeries. My Internist said I was so sick that no doctor would touch me for a gastric surgery.
My GI, C/R surgeon and she said nothing to me about loosing weight before my surgeries. My surgeon did his fellowship, or whatever they call the training, at the Cleveland Clinic. He is a overweight himself and a jolly upbeat man . I asked him if my weight was going to be a problem and he said no. I was the UCer that gained and kept all the prednsone weight. I think there are 2 general types of UC people. The ones that get grossly underweight and the ones that get fat. It is hard to loose prednisone or any other weight when you are so ill!
My surgery went well but I was hospitalized for 16 days afterwards. I had big time dehydration problems. He wouldn't let me go home until everything was under control. Talk about PTSD events. I was entertained by the helicopter paramedics several nights when none of the nurses could get an IV started. Hard to do when the patient is dehydrated. Thank God my take down was 8 weeks after the first surgery.
I suggest you find another surgeon. My GI didn't refer me to one of my surgeons partners because she was the type of surgeon that preached about being fit. She covered for the group's patients one weekend and she had no bedside manner.
I feel bad for all that you are going through. It's hard to be so ill. Things will get better. It might take a while but you will get better.