If it is an intrahepatic bile duct stone 0.8cm, no treatment is needed. If it is a common bile duct stone 0.8cm, it usually has some abdominal pain symptoms and needs surgery. The reasons are as follows: 1. When eating an oil meal, after the gallbladder contracts to discharge the bile, the stone may be stuck to the lower part of the common bile duct, such as at the sphincter of Oddi, with the action of bile flow, so it will cause acute obstructive cholangitis, which will be septic in severe cases. Acute obstructive purulent cholangitis is sometimes very dangerous and life-threatening; 2. Bile duct stones can easily cause pancreatitis, i.e. biliary pancreatitis. Because it causes irregular contraction of the sphincter of Oddi, it can easily cause acute pancreatitis, and moderate or severe pancreatitis can sometimes be life-threatening. Therefore, early surgery is recommended for patients with common bile duct stones, and there are more surgical options, including ERCP (transendoscopic retrograde cholangiopancreatography), combined choledochoscopy and laparoscopy, etc. In special cases, open surgery is also possible. ERCP is performed through the mouth, stomach and duodenum, and the gastroscope is inserted into the duodenal papilla to remove the stone through the papilla.