Biliary obstruction: This is the most common cause of white or clay-colored stool, as it prevents bile from reaching the intestines, resulting in stool that lacks the normal brown pigment.

Pancreatic insufficiency: Conditions like pancreatitis or pancreatic cancer can lead to a deficiency in pancreatic enzymes, which are necessary for proper digestion and absorption of nutrients, potentially causing changes in stool color.
Gastroenteritis: Certain infections can cause a temporary change in stool color, including white or pale stools, due to inflammation and disruption of the normal digestive process.
Malabsorption: Conditions such as celiac disease or Crohn's disease can lead to malabsorption of fats and other nutrients, resulting in pale or white stools.

Hepatocellular carcinoma: Although less common, liver cancer can cause biliary obstruction, leading to white stools. Early detection is crucial for treatment.
Cholangiocarcinoma: Cancer of the bile ducts can also cause obstruction, leading to changes in stool color. It is essential to consider this diagnosis to initiate appropriate treatment.
Primary sclerosing cholangitis: This chronic liver disease can cause scarring and narrowing of the bile ducts, potentially leading to biliary obstruction and white stools.

Alagille syndrome: A genetic disorder that affects the liver and can cause a reduction in the number of bile ducts, leading to bile build-up and potentially white stools.
Caroli's disease: A rare congenital disorder of the bile ducts that can cause recurrent cholangitis and potentially lead to changes in stool color.
Primary biliary cirrhosis: An autoimmune disease of the liver that can cause progressive destruction of the bile ducts, potentially leading to white stools.