Bile is a digestive juice that your liver produces. Your gallbladder stores it, and from there, it flows into the upper part of your small intestine to help you digest food. At the same time, your pancreas produces juices that are important for digestion. Both bile and your pancreatic juices flow to your small intestine through a common duct that is opened and closed by a round valve. The valve is a muscle called the sphincter of Oddi.
In rare cases, the sphincter of Oddi goes into spasm. It clamps shut and cannot relax. This is called Sphincter of Oddi dysfunction (SOD). The condition causes intense belly pain. Your digestive juices back up into your pancreas and into the bile ducts of your liver.
Doctors aren’t sure why SOD happens, but you’re most at risk for this condition if you’ve had your gallbladder removed. If you have had gastric bypass weight-loss surgery, you may also develop it.
The main symptom of SOD is severe abdominal pain that comes and goes. All the symptoms can feel similar to a gallbladder attack. You may have pain in your upper abdomen that seems to move, or radiate, into your right shoulder. You may also have chest pain that feels like a heart attack. Symptoms that go along with the abdominal pain include:
Loss of appetite
Each year, about half a million people in the U.S. have their gallbladder removed. Up to 20 percent of people may have some symptoms of SOD afterward. Risk factors for SOD are similar to those for gallbladder disease. They include:
Being middle-aged or older
Having high cholesterol
Having had gastric bypass surgery for weight loss
Your doctor may suspect SOD if you have bouts of abdominal pain after your gallbladder was taken out. Of the 10 to 20 percent of people who have abdominal pain after this procedure, about half will have blood tests, imaging tests, or other diagnostic tests that suggest SOD. These tests may include:
Blood tests for higher-than-normal liver or pancreatic enzymes
Ultrasound of the bile duct, liver, or pancreas
MRCP, or magnetic resonance cholangio-pancreatography, an imaging study of the bile and pancreatic ducts
ERCP, endoscopic retrograde cholangio-pancreatography, a procedure that looks directly inside the duct system while taking pictures and measuring pressure
Your doctor may also test you for SOD if you are feeling severe abdominal pain after recovery from a gastric bypass surgery.
Treatment of SOD depends on the type you have. It's also affected by how severe your symptoms are. If diagnostic tests show that your symptoms stem from a backup of digestive juices into your liver or pancreas and you are having frequent symptoms, you may have your sphincter of Oddi muscle cut surgically during an ERCP exam. This procedure is called sphincterotomy. It’s generally effective and relieves symptoms of SOD about 70 percent of the time.
If you have type III SOD, you have symptoms of SOD, but your diagnostic tests do not show actual evidence of blockage or backup of digestive juices. Treatment for type III SOD starts with medications like pain relievers, muscle relaxants, and occasionally antidepressants. Sphincterotomy is done only if medications don’t help.
Most complications of SOD are seen in people who need to have their bile duct system examined. Up to 10 percent of people develop pancreatitis after the medical procedure ERCP, with or without surgery to cut the sphincter. Pancreatitis is a severe swelling and irritation of the pancreas. This complication usually clears up within a few days of hospital treatment, but for a few people it may result in weeks or months of hospitalization.
Complications from surgically cutting the sphincter of Oddi may include bleeding, infection, and delayed narrowing of the duct system because of scarring.
Let your doctor know about severe abdominal pain that is not going away or keeps coming back. Also, let your doctor know if you have these symptoms, especially after gallbladder surgery:
If you have an SOD diagnosis or you are recovering from sphincterotomy, follow all your doctor's orders. Take all your medications as directed, and make sure your doctor knows about any other medications you take, including over-the-counter medicines, supplements, or herbs.
Tips for living with SOD include:
Avoiding high-fat foods
Maintaining a healthy weight
Eating smaller, more frequent meals