Light-colored stools contain no bile, indicating an impaired liver or a bile duct blockage, according to Healthline. Light-colored stools may be a symptom of gallstones, congenital structural defects in the biliary system, hepatitis, biliary cirrhosis or sclerosing cholangitis.
Gallstones are hard, small deposits that form in the gallbladder, obstructing the flow of bile, explains Healthline. Certain medications and surgery may treat the problem. Hepatitis, which is the swelling and inflammation of the liver as a result of drinking too much alcohol, viral infections or taking certain medications, may damage the liver, affecting the production or flow of bile.
Biliary cirrhosis is a life-endangering condition that occurs due to damage of bile ducts in the liver, interrupting the flow of bile, notes Healthline. As of 2015, doctors do not yet know the exact cause and treatment for the condition. Prescription medications and surgical procedures may help counter sclerosing cholangitis, a condition of the biliary system that causes swelling and scarring of bile duct throughout the body.
Tumors and cysts in the biliary system may also inflame the liver or interrupt the flow of bile, states Healthline. A physical and medical examination may help provide a diagnosis for light-colored stools. Blood tests, abdominal ultrasound and imaging techniques may also help diagnose the condition.