Sphincter of Oddi Dysfunction | Loyola Medicine

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Sphincter of Oddi Dysfunction

Overview and Facts about Sphincter of Oddi Dysfunction

The sphincter of Oddi is a smooth muscle found at the end of the common bile duct and pancreatic duct. When you eat, this muscle relaxes and pancreatic juice and bile flow into your intestines. When you have sphincter of Oddi dysfunction (SOD), your sphincter muscle doesn’t function properly and fails to open. This failure leads to a backup of bile and pancreatic juice and can cause severe abdominal pain.

There are two types of SOD. Biliary dysfunction occurs when digestive juices back up in the liver’s bile ducts. The other type, pancreatitis, manifests itself when the backup occurs in your pancreas and causes inflammation.

Symptoms and Signs of Sphincter of Oddi Dysfunction

Because sphincter of Oddi dysfunction causes bile and pancreatic juice to back up into the digestive tract, it can lead to a wide range of symptoms. Some of the most common signs of SOD include:

  • Abdominal pain
  • Fever
  • Nausea
  • Vomiting

The symptoms of SOD tend to worsen after meals or from taking opiates. It can also persist after gallbladder removal surgery.

Causes and Risk Factors of Sphincter of Oddi Dysfunction

While the root cause of sphincter of Oddi dysfunction is unknown, several risk factors have been identified. If you’ve had your gallbladder removed, your risk is increased. Middle-aged women are also at a higher risk.

Several theories about the cause of SOD exist, and include the presence of microscopic stones in your bile, or inflammation in your upper small intestine.

Tests and Diagnosis of Sphincter of Oddi Dysfunction

When your doctor thinks you may have SOD, they request a blood test to measure pancreatic and liver enzymes. If your enzyme levels are high, these laboratory tests are followed with radiographic tests. The most common is a quantitative hepatobiliary scintigraphy, where your doctor injects a radioactive substance into your blood that allows them to monitor how your liver and biliary tract function.

To fully diagnose this digestive health condition, your doctor may need an endoscopic retrograde cholangiopancreatography (ERCP). During this procedure, they insert a small camera on a thin tube into your mouth and through your digestive tract in order to examine your bile and pancreatic ducts. They may measure your duct diameter, drainage and pressure.

Treatment and Care for Sphincter of Oddi Dysfunction

When you have a mild case of sphincter of Oddi dysfunction, you may improve your symptoms by switching to a low-fat diet. Your doctor may also recommend taking:

  • Antispasmodics
  • Nifedipine
  • Nitroglycerin
  • Non-addictive analgesics

If a more aggressive treatment is needed, your doctor may inject Botox into your sphincter muscle, causing it to relax, or complete a sphincterotomy, where the doctor cuts the sphincter of Oddi, allowing your digestive juices to flow.