What Is Sphincter of Oddi Dysfunction?

The sphincter of Oddi is a small muscle valve that helps control the flow of bile and digestive juices from the liver and pancreas into the small intestine. When this valve does not relax or open properly, it is called sphincter of Oddi dysfunction (SOD).

The exact cause of SOD is not fully understood. It may happen when the sphincter muscle spasms or becomes narrowed from inflammation or scarring.

Risk factors include:

• Gallbladder removal surgery
• Recurrent pancreatitis
• Gastric bypass surgery
• Being female
• Middle age

This condition can block the normal movement of digestive fluids, leading to pain and irritation in the digestive system. In some cases, it may also contribute to pancreatitis.

Symptoms

Symptoms of SOD often come and go. The pain can be severe and may feel similar to gallbladder pain, even after the gallbladder has been removed.

Symptoms may include:

• Pain in the upper abdomen
• Pain spreading to the back or right shoulder
• Nausea or vomiting
• Bloating or digestive discomfort
• Loss of appetite
• Weight loss
• Episodes of pancreatitis

How Is It Diagnosed?

Diagnosing SOD can be challenging because symptoms may resemble other digestive conditions. Providers begin by reviewing symptoms, medical history, and prior surgeries.

Testing may include:

• Blood tests to check liver and pancreatic enzymes
• Ultrasound imaging
• MRCP scans to examine bile and pancreatic ducts
• Endoscopic ultrasound (EUS)
• ERCP procedures in selected cases

These tests help rule out other causes of abdominal pain and evaluate how well the bile ducts and pancreas are functioning.

How Is It Treated?

Treatment depends on the severity of symptoms and the type of SOD involved.

Conservative treatment may include:

• Medicines to relax the sphincter muscle
• Pain management
• Eating smaller meals
• Limiting high-fat foods
• Avoiding alcohol and smoking

For more severe or ongoing symptoms, providers may recommend procedures such as:

• Endoscopic sphincterotomy to open the muscle valve
• Botox injection to temporarily relax the sphincter

Many people experience symptom relief after treatment, though some may need ongoing care or monitoring.