Hi,I had same surgery 10 years ago.I had gone from11 stone down to 7 in the space of 5 weeks.It was so hard after the surgery to put back on weight even though I was on high doses of steroids.And yes,I was exhausted for months after.Still get very tired when i get flare ups,its a tiredness that sleep just doesnt help with.
Have you tried nutrient drinks?I know I had to drink 4 cartons of ensure a day,for a while after surgery.I always say its harder to put weight on than lose it,I have tried both.I think when your'e underweight your stomach is so small you can only physically fit small amounts of food in.Also remember you will obviously be running to the loo more as the waste has less of a journey now.Rest as much as you can,remember even lying awake n your bed is a good rest and try eating high fat foods for a while.You will be back to yourself soon,don't worry.