Well, I know we have a few boardies here who had good results with their NHS LIS! A couple of the UK boardies had other complications, but not as a result of the surgery. Maybe you'll get to hear from them soon!
Just a little cereal milk is not much dairy in my book! Too much fib(e)r(e) can definitely be a problem! You probably only need around 25-30 grams a day..depending on your size.
After four years, who would not be fed up? I say, you are a patient man having lasting this long!