August 2011, Volume 41 Number 8 , p 42 - 45
AFTER EXPERIENCING recurrent right upper quadrant (RUQ) pain, fatty food intolerance, and nausea, Ms. F, 55, was diagnosed with cholecystitis. She underwent a laparoscopic cholecystectomy, which resolved her symptoms. But approximately 5 months after surgery, Ms. F developed RUQ pain described as "knifelike" and frequently associated with nausea and vomiting after eating a fatty meal. Ms. F stated these symptoms were worse than those she experienced before the cholecystectomy. Her healthcare provider referred her to a gastroenterologist.The gastroenterologist ordered a complete blood cell count and complete metabolic panel, in addition to dynamic hepatobiliary scintigraphy (also known as a HIDA scan) with cholecystokinin stimulation. The purpose of dynamic hepatobiliary scintigraphy is to assess common bile and pancreatic duct patency, hepatic function, and sphincter of Oddi (SO) function.All blood work results were within normal limits, but hepatobiliary scintigraphy suggested sphincter of Oddi dysfunction (SOD). The gastroenterologist prescribed an anticholinergic agent along with a proton pump inhibitor, an antispasmodic, and analgesia. But when Ms. F's symptoms persisted, the gastroenterologist referred her to a gastroenterologist specializing in diagnostic and therapeutic endoscopy.This article describes the physiology, diagnosis, and management of SOD so you'll be better prepared to recognize this disorder and support your patient.The SO is a muscular structure surrounding the site where the distal common bile duct and main pancreatic duct join at the ampulla of Vater. (See Finding the trouble spot.) It has three primary functions: * maintaining unidirectional flow of bile and pancreatic juices into the duodenum * redirecting hepatic bile to the gallbladder for storage * preventing backflow of duodenal contents into the pancreaticobiliary tract.1Normally the SO is closed, opening only when bile and pancreatic enzymes are needed in the duodenum after food ingestion.