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Sphincter of Oddi dysfunction is an uncommon condition that impairs the flow of bile and pancreatic fluids to the intestines. It can cause a number of uncomfortable symptoms, including nausea, vomiting, and sharp abdominal pains after eating. The disorder can occur if the sphincter is too narrow or becomes blocked due to inflammation, congenital abnormalities, or surgical complications. Doctors may be able to treat mild problems with the sphincter of Oddi with prescription medications, but surgery is often necessary to ensure that problems do not return.
The sphincter of Oddi is a smooth, tubular muscle structure that opens into the duodenum, the upper part of the small intestine. It attaches to the pancreatic duct and the common bile duct from the gallbladder. The sphincter contracts and expands to regulate the flow of bile and pancreatic fluid into the duodenum, which helps to ensure proper digestion. In the case of sphincter of Oddi dysfunction, fluids back up into the ducts because the sphincter cannot relax and drain them.
Most doctors recognize two types of sphincter of Oddi dysfunction. Papillary stenosis refers to physical abnormalities that cause the sphincter to narrow. The most common cause is scarring due to bile or pancreatic duct inflammation. Scarring may occur if a person has gallstones or undergoes gallbladder, pancreas, or duodenum surgery. Congenital conditions may also affect the size and shape of the sphincter of Oddi.
The second type is called biliary dyskinesia and involves changes in the sphincter's functionality. Sudden increases in bile duct pressure or adverse reactions to muscle-relaxing hormones can impair the muscle's ability to pump fluids. The causes of biliary dyskinesia are not well understood, but patients are more likely to develop the condition after undergoing gallbladder removal surgery.
Symptoms can vary depending on the severity of the disorder. Most people notice sharp, shooting pains in their upper abdomens, usually following big meals. A person may also experience frequent bouts of nausea, stomach cramps, vomiting, and loss of appetite. If the condition goes untreated, fluid backup can lead to pancreatitis and gallbladder inflammation. Symptoms tend to become more severe and constant once the organs are involved.
Doctors can usually diagnose sphincter of Oddi dysfunction by evaluating symptoms, counting liver and pancreatic enzymes in blood samples, and taking abdominal x-rays. If it is unclear what is causing fluid backup, a specialist can use an endoscopic camera to closely inspect the duodenum and sphincter.
Anti-inflammatory medications and a low-fat diet help some people recover from biliary dyskinesia. If the problem is structural, however, surgery is usually needed. A surgeon can implant a stent into the sphincter to hold it open and promote better fluid flow. Occasionally, the entire sphincter needs to be removed and the ends of the ducts are connected directly to the duodenum. Most patients are able to recover from surgery in less than three months and do not experience recurring issues.