Light-colored, white or clay-colored
What it may mean:
A lack of bile in stool. This may indicate a bile duct obstruction.
Possible dietary reasons:
Certain medications, such as large doses of bismuth subsalicylate (Kaopectate, Pepto-Bismol) and other anti-diarrheal drugs.
Stool color: When to worry - MayoClinic.com
I think this^^^^^
Go see your doc again. Not much here we can really do