Pinaverium Bromide in Post-cholecystectomy Sphincter of Oddi Dysfunction

Inclusion Criteria: * Chief complaint of upper right abdominal pain following LC (within 2 weeks to 6 months) at a hospital visit, but not a pain caused by surgical incision, lasting 3 to 5 minutes each time, without a history of other biliary tract operation * No presence of intestinal obstruction as evidenced by plain abdominal X-ray, with peptic ulcer and duodenal diverticulum ruled out through barium meal examination or gastroscopy * No other obvious abnormalities as evidenced by abdominal ultrasound B and MRCP, except for bile duct dilation * Patients with biliary-type sphincter of Oddi dysfunction (SOD) who are classified as SOD type II (biliary-type abdominal pain accompanied by hepatic enzyme elevation or common bile duct (CBD) dilation) and SOD type III (only biliary-type abdominal pain) according to Geenen-Hogan classification criteria Exclusion Criteria: * Postoperative biliary calculi, benign biliary stenosis, bile duct infection, overlong residual cystic duct (\> 0.5cm), biliary tumors, etc. * Peptic ulcer, duodenal diverticulum * Pancreatitis, pancreatic-type SOD * Adhesive intestinal obstruction * Postoperative irritable bowel syndrome (IBS) * A history of abdominal operation or other surgery * Pregnant and lactating women * Use of other drugs from one week after LC to enrollment, including antispasmodic drugs, analgesics, choleretic agents, calcium ion antagonists and GI motility drugs * A history of allergy to Pinaverium Bromide / Danshu Tablets