The sphincter of Oddi is a muscular valve in the digestive tract that opens and closes. It allows digestive juices, bile, and pancreatic juice to flow properly through the ducts from the liver and pancreas to the small intestine. These substances are essential for the digestive process.
When the sphincter of Oddi isn’t working properly, it doesn’t open when it should. This causes an obstruction that prevents bile and pancreatic juice from flowing properly to the small intestine, leading to a backup of digestive juices that can cause severe pain in the abdomen.
Experts aren’t exactly sure what causes sphincter of Oddi dysfunction. Many suspect it may be related to microlithiasis (the presence of microscopic stones in the bile) and inflammation of the first section of the small intestine.
Because the sphincter of Oddi covers two ducts (one connected to the liver and one connected to the pancreas), there are two types of sphincter of Oddi dysfunction (SOD). The first is marked by a back up of digestive juices in the liver’s bile ducts. This is referred to as “biliary dysfunction.”
The other occurs when the back up affects the pancreas, causing inflammation known as pancreatitis.
These two types of sphincter of Oddi dysfunction can be further divided into three categories. With category I, the most severe, patients have pain, abnormal blood test results, diagnosable drainage issues, and abnormal findings on imaging (dilated common bile duct for biliary type I and dilated pancreatic duct for pancreatic type I). With category II, patients have pain and only one or two of the criteria required to diagnose category I. With category III dysfunction, there are no clear lab findings or abnormalities, and the only sign of a problem is abdominal pain.
It’s more difficult to diagnose type III sphincter of Oddi dysfunction than the others, and it can be harder to treat, as the percentage of patients showing improvement following therapies is lower.
The symptoms of sphincter of Oddi dysfunction may come and go over time. They also may vary in severity from one occurrence to the next. Common symptoms include:
- abdominal pain, which is the most prevalent symptom (usually epigastric or right upper quadrant pain)
Despite the causes being unknown, it appears that some people are more at risk of developing sphincter of Oddi dysfunction than others. This includes people who have had their gallbladders removed. Some research suggests that
If you present symptoms of sphincter of Oddi dysfunction to your doctor, they will try to rule out other possible causes of your symptoms. Some serious conditions they must rule out include cancer of the pancreas or bile ducts, peptic ulcer disease, or stones in the bile ducts. Heart conditions, such as angina or ischemia, can also cause pain that comes from the abdomen.
Your doctor may run blood tests or use imaging studies to help with the diagnosis. Ultrasound, hepatobiliary scintigraphy, or magnetic resonance cholangiopancreatography (MRCP) may be ordered. They may also perform sphincter of Oddi manometry, a procedure that involves inserting a small plasic tube into the pancreatic and/or bile ducts to directly measure the pressure of the sphincter of Oddi. You will be sedated for the manometry procedure. Sphincter of Oddi manometry is the gold standard for diagnosis of SOD. However, it’s also an invasive test, so you must weigh the risks and benefits.
Nitrates and calcium channel blockers have been used to help relieve symptoms. These medications can sometimes stop the spasms associated with sphincter of Oddi dysfunction and should be offered first in type III SOD patients before suggesting invasive therapies.
For those with severe sphincter of Oddi dysfunction pain, your doctor may recommend a sphincterotomy. During this procedure, you’re either sedated or put under anesthesia. Your gastroenterologist will push a thin endoscopic instrument through your mouth into your small intestine, where your sphincter of Oddi is located, and cut the muscle. Your doctor will also check for any gallstones within the bile ducts.
This kind of procedure is usually attempted only after medications have failed to relieve sphincter of Oddi dysfunction pain, because of a high risk of complications. Risks can be as small as mild inflammation in the pancreas to severe infections resulting in long hospital stays.
There isn’t much scientific literature on diet therapies for sphincter of Oddi dysfunction, nor is there a specific diet for people with sphincter of Oddi dysfunction. However, you may notice that some foods trigger your symptoms worse than others. Some people feel ill every time they eat, while others are affected by specific foods only on rare occasions.
To determine what your trigger foods are, you might want to try an elimination diet — just be aware that this approach isn’t backed by scientific research. Always consult your doctor before making any dietary changes. An elimination diet involves systematically removing foods from your diet that are known to trigger sphincter of Oddi dysfunction symptoms in some people. These include:
- coffee and other caffeinated beverages
- red meat and pork, even when cut lean
- fried, fatty, or greasy foods
- spicy foods
- fruits, especially acidic fruits
- fibrous raw vegetables
With proper treatment or medication, up to 70 percent of people with sphincter of Oddi dysfunction experience long-term relief, depending on the type of SOD.
Sphincter of Oddi dysfunction does not necessarily reduce a person’s life expectancy, though it can very much reduce their quality of life. Those with severe cases of sphincter of Oddi dysfunction may have a lower life expectancy than the general population and those with more mild cases of the disorder.
Sphincter of Oddi dysfunction can be a challenging medical condition. For the best chance of recovery, it’s important to stick to your treatment plan and consult your doctor before making any dietary of lifestyle changes. Talk to your doctor if your treatment plan doesn’t seem to improve how you feel. They will work with you to find a way to bring you relief.