I had a liver function test done and although my ast levels went down my ast is still elevated.?

It is at 56 when normal range is between 6 and 40.I'm not a smoker or drinker I am 40 pds. overweight though with high cholesterol. I'd had pain in the liver region after I had my gallbladder removed a few months ago and although the pain was constant then it had considerably subsided but then I was put on zocor 20mg once a day for the cholesterol and I've taken it for only 3 days and the pain is back and it's constant again like before. I've had ultrasounds done which show no inflammation so the dr says it's probably a fatty liver. But a fatty liver doesn't show up on an ultrasound I know cause I've asked the dr. When I had the gallbladder removed I asked the dr who did the surgery how my liver looked and he said fine so I'm left with the nagging question again if everything looks good then why are my alt's elevated????? I am going to the dr for this by the way but hearing input never hurts. So thanks for sharing your story if you're gone thru the same thing or even if you haven't but have something to share thanks too.