What is the sphincter of Oddi dysfunction?
Digestion, through which the human body transforms the food we eat into the energy we need, is a complex process. Most people know about the roles that saliva in the mouth and acid in the stomach play in digestion. However, other glands, chemicals, and muscles also play important roles in the process. The liver, the pancreas, and the sphincter of Oddi are among these.
The liver provides a chemical called bile to the digestive process, and the pancreas provides pancreatic juice. These important chemicals flow from the liver and pancreas into the small intestine to help with digestion. The flow of these chemicals is controlled by muscle called the sphincter of Oddi.
A sphincter is a muscle (usually round) that can open and close. When it’s working properly, the sphincter of Oddi opens to allow bile and pancreatic juice to flow through and then closes again. However, in a condition called sphincter of Oddi dysfunction, the sphincter muscle does not open when it should. This prevents the bile and pancreatic juice from flowing through and causes a backup of digestive juices. The backup can cause bouts of severe pain in the abdomen.
There are two basic types of sphincter of Oddi dysfunction:
- If the digestive juices are backing up in the bile ducts from the liver, the term is biliary dysfunction.
- If the backup is occurring in the pancreas, you may hear your doctor use the term “pancreatitis.” This means the pancreas is becoming inflamed.
There are also three categories of sphincter of Oddi dysfunction:
- In categories I and II, doctors can find clear evidence of the dysfunction, such as abnormal blood test results or a dilated bile duct, which might be found by using an ultrasound test.
- In category III dysfunction, there are no clear-cut lab findings or abnormalities, and the only evidence of the dysfunction is the abdominal pain. The pain is believed to be caused by a sudden spasm of the sphincter of Oddi. Type III dysfunction is much more difficult for doctors to diagnose.
Who is at risk for developing this condition?
People who have had their gall bladders removed are most likely to develop sphincter of Oddi dysfunction. The procedure by which the gall bladder is removed is called cholecystectomy, and some doctors refer to sphincter of Oddi dysfunction as post-cholecystectomy syndrome. Middle-aged women also appear to be at increased risk for the condition, although doctors aren’t sure why.
What are the symptoms of sphincter of Oddi dysfunction?
Abdominal pain is the most common symptom; less common symptoms include nausea, vomiting, fever, chills, and diarrhea. These symptoms can come and go, and can be mild one time and severe the next.
How is sphincter of Oddi dysfunction diagnosed?
When sphincter of Oddi dysfunction is suspected, your doctor will first check to see if the abdominal pain is caused by another condition. It is important to make sure patients with abdominal pain don’t have serious conditions such as cancer of the pancreas or bile ducts, peptic ulcer disease, or stones in the ducts that carry the bile from the liver. In some cases, even heart conditions such as angina or ischemia can cause pain that seems to be coming from the abdomen.
Your doctor may want to take a close look at the sphincter of Oddi to see if it is functioning normally. This is done by placing a small plastic tube into the pancreas duct or bile duct near the sphincter of Oddi to measure how well it is contracting and expanding. Patients are placed under sedation for this procedure, which is called sphincter of Oddi manometry.
What is the treatment for sphincter of Oddi?
In patients where the pain is not too severe, especially in hard-to-diagnose category III patients, medical treatment is usually the first course of action. Some patients can get relief by using pain medications or drugs that prevent the sphincter of Oddi from having spasms.
When the pain is severe, and tests have clearly identified the pain as being caused by sphincter of Oddi dysfunction, your doctor may refer you for a surgical procedure called sphincterotomy. You’ll either be sedated or put to sleep under anesthesia for this procedure. A surgeon will pass a thin instrument into the area of the small intestine where the sphincter of Oddi is located and cut the muscle.
During this procedure, the surgeon will also make sure that there aren’t any stones in the gall bladder (if it hasn’t already been removed) or in the bile ducts.
In most cases, sphincterotomy can achieve good relief of the pain and other symptoms of sphincter of Oddi dysfunction. However, this procedure is usually tried only after medical treatment has failed. Sphincterotomy is a difficult procedure that has a fairly high risk of complications. About 5% to 15% of patients experience complications such as mild inflammation of the pancreas, but in some cases the complications are severe and can require a long stay in the hospital.
- International Foundation for FuThe Cleveland Clinic Foundationnctional Gastrointestinal Disorders. Sphincter of Oddi Dysfunction Accessed 9/17/2013.
- Hogan WJ. Gastroenterol Hepatol (N Y). 2007;3(1):31-5. Diagnosis and treatment of sphincter of oddi dysfunctionAccessed 9/17/2013
- Marks JM, Ponsky JL. Chapter 3. In: Zinner MJ, Ashley SW, eds. Maingot’s Abdominal Operations. 12nd ed. New York: McGraw-Hill; 2013. Endoscopy and Endoscopic Intervention Accessed 9/17/2013