A bile duct dilates when an obstruction forms inside it and the duct has to expand to allow bile to travel among the liver, gallbladder, pancreas and small intestine. The first signs of a dilated bile duct range from abdominal pain to dark urine and jaundice, according to Healthline.
The doctor uses imaging scans to identify the obstruction causing the bile duct to dilate. Gallstones and various types of carcinomas can lead to blockage, but many other possible causes exist as well, such as trauma, anomalous narrowing of the ducts, cysts, swollen lymph nodes, pancreatitis, cirrhosis of the liver and hepatitis, as stated by Ultrasound Cases and Healthline.
Once the doctor has identified the cause for the obstruction, he chooses a treatment designed to address that cause. If gallstones are causing the blockage, the doctor may recommend removing the gallbladder. Other treatment options are to take smaller stones out of the bile duct or insert a stent into the duct to improve bile flow. If the cause is cancer, the doctor performs the treatment to address the tumors, which can involve removal of the gallbladder as well. People who maintain healthy weight levels are less likely to develop the gallstones, which are the most common cause of blockages, notes Healthline.