What can cause the stool to float and change color?

Hello doctor,

About 18 months ago, my stomach distended, and my stool turned from brown to light brown and eventually yellow. After that, I started to lose weight at a rapid rate, 40 lbs in 15 months. I was given multiple blood tests, an upper endoscopy, and abdominal ultrasounds. The only thing of significance was minor gastritis and some gallbladder sludge, nothing else. I have no hepatitis or autoimmune issues. I do not have Wilson's disease. 11 months ago, I had a blood test showing elevated ALT liver enzymes and slight liver enlargement. Total bilirubin was elevated as well. I had more ultrasounds, a liver biopsy, a colonoscopy, abdominal CT scan and MRI. Nothing was out of the ordinary with the imaging, except more sludge and possibly small stones. The biopsy showed 'minimal portal and lobular inflammation' with an indication of a resolving process. My liver enzymes continue to be elevated, my stool is constantly yellow and now for the last six months, it floats. At this point, the doctors continue to investigate, but cannot figure out what is happening.

I do not drink, use drugs or anything of the sort. I am seeking advice as to what the doctors might not be seeing. I do not seem to have any type of GI or surrounding structure cancers. What else could cause ALT liver enzymes to elevate? Lastly, what would cause a sudden change in stool color and eventually floating? Is there any connection with the liver or vice versa? Could that help explain the weight loss? I cannot gain the weight back no matter what I do. I have stabilized at 196 lbs and I am 6 feet. Any help you can give would be much appreciated.