Tough to say without the benefit of the blood test results or examination. The liver function tests as well as the ultrasound is a reasonable first step to explore what is going on.
Pale stools can be indicative of biliary obstruction (caused by a stone for instance), and itching can be a symptom of biliary sclerosis. Again, the ultrasound and liver function tests would be the first steps in diagnosing these diseases.
I would followup these results with your personal physician or consider a gastroenterology referral.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b