Bile duct obstruction occurs when the bile ducts, which carry bile from the liver to the small intestine, become blocked. This blockage can be caused by various factors, including gallstones, tumors, or inflammation. When the bile cannot flow properly, it can lead to a buildup of bile in the liver, causing jaundice, dark urine, and pale stools. Symptoms of bile duct obstruction may include abdominal pain, itching, and nausea. Diagnosis typically involves imaging tests like ultrasound or CT scans to identify the cause of the blockage. Treatment options may include endoscopic procedures, surgery, or medication to relieve the obstruction.