I had RNY, but my liver enzymes were elevated the first year or so. My PCP said thought it was probably fatty liver, but then I read online (some reliable medical site) that elevated liver enzymes were not uncommon after WLS because the rapid weight loss can be really hard on livers. I had them re-tested later, and they were normal - so I think that's what was going on. Not sure why this possibility didn't occur to my PCP, but maybe she doesn't see many bariatric patients.
I'm not saying this the cause of yours, but I think it was in my case. In any case, mine are normal now.
EDITED to add I just re-read your post and you said your liver was enlarged. So your enzyme levels may be due to something else. I don't know if my liver was enlarged since that was never checked - but my enzyme levels were definitely high.