What Is Sphincter Of Oddi Dysfunction

Introduction

Have you heard about the sphincter of oddi & wondered about it, where is its place, and what its function is? Is it necessary in our body? What happens when it becomes dysfunctional? Therefore, Here, at Klarity we will provide you with all the answers you need, let’s go.

What is the sphincter of oddi dysfunction (SOD)?

The sphincter of Oddi is responsible for regulating the flow of bile & pancreatic juices to the small intestine, which is important for the process of digestion. Therefore, it helps to prevent the return of the juices once again to the bile duct & pancreas.¹

When the sphincter becomes nonfunctional, the muscle of the sphincter does not work well, which will lead to stasis and the return of Bile and pancreatic juices outside the sphincter. As a result, Bile will return to the liver, and juices will return to the pancreas, which will harm the liver and pancreas because these juices are needed for digestion, so instead of digesting food, they will damage our internal organs, leading to severe abdominal pain. That will develop one of two conditions:

• Biliary dyskinesia: in this case, the bile returns to the liver.
• Pancreatitis: happens when the pancreatic juices return to the pancreas.

What are the types of sphincter of oddi dysfunction?²

There are three types of the sphincter of Oddi dysfunction categorized according to the clinical picture of the patient, the severity of abdominal pain, and levels of liver enzymes and other blood tests. Therefore they are classified as follows:

• Type I: This type is characterized by the presence of abdominal pain with abnormal liver enzymes and dilated common bile duct.
• Type II: This type is characterized by the presence of pain and only one diagnostic finding.
• Type III: This type is characterized by the presence of only biliary pain

Type III is difficult to confirm the presence of dysfunction as the only evidence that appears in this type is abdominal pain only.

Who is at risk for the sphincter of oddi dysfunction?¹

•  Middle-aged women with uncertain reasons for developing this disease.
• Patients who do cholecystectomy may develop what is called post-cholecystectomy, which means dysfunction in the sphincter of Oddi.
• Patients have jaundice.

What are the symptoms of the sphincter of oddi dysfunction?⁵

• Abdominal pain (the most common symptom appear) 
• Diarrhea
• Vomiting
• Chill
• fever 

How can the sphincter of oddi be diagnosed?

As we said before, it is hard to discover as it has symptoms similar to other diseases, but we can still do blood tests, imaging, and endoscopes to make sure you have the sphincter of Oddi dysfunction.

What are the steps to confirm the sphincter of oddi dysfunction?⁴

Patient history and physical examination

• The doctor will do a complete checkup to make sure the abdominal pain is not related to problems in the liver or pancreas or any of the ducts between them, like the presence of cancers, stones, or ulcers.
• Even sometimes, heart disease like angina pain seems to come from the abdomen.

Laboratory tests

• Therefore, for more confirmation, your caregiver asks to do liver and pancreatic enzyme tests like:
  • Alkaline phosphatase 
  • Transaminase
  • Amylase 
  • Lipase 

when the results of tests are above normal this may be oddi dysfunction, but if it is so high maybe it is other conditions from the list that doctors exclude.

Imaging studies

1. Noninvasive methods:
   • X-ray and Computed tomography(CT) scans take a deeper look at the structures inside our body, but they are still not completely accurate.
   • Ultrasound-explain what ultrasound is used for 
   • Magnetic resonance cholangiopancreatography (MRCP): In which we use magnets & dye to take certain images of the bill & pancreatic ducts.
   • Endoscopic retrograde cholangiopancreatography (ERCP): this test is like an endoscope, but it is specific for ducts and the sphincter in this test we insert a small tube to reach to small intestine then we inject a dye that makes ducts and the sphincter more prominent in x-ray to see more clear the problem so sometimes else we send air through this tube to measure the pressure of air in the sphincter that is called manometer.

2. Invasive methods:
   • Endoscopic retrograde cholangiopancreatography (ERCP): this test is like an endoscope, but it is specific for ducts and the sphincter in this test we insert a small tube to reach to small intestine then we inject a dye that makes ducts and the sphincter more prominent in x-ray to see more clear the problem so sometimes else we send air through this tube to measure the pressure of air in the sphincter that is called manometer.
   • Sphincter of Oddi manometry: this is an Invasive procedure to measure sphincter pressure, therefore the doctor enters a plastic tube near to pancreatic duct or bill duct near to sphincter of Oddi to measure how well the sphincter will contract and expand. 

Treatment and management⁴

There are two options for treatment if the pain is mild and does not continue all the time, therefore, it only needs medical treatment. If the pain is so severe, your doctor refers you to an endoscopic specialist for sphincterotomy.

1. Medical treatment:
   • In this approach, we depend on using analgesic and antispasmodic. Lots of studies work on different drugs to be used in type I and II like calcium channel blockers, nifedipine, and nitrates, but all studies found that all drugs decrease pain and symptoms of the disease but can’t be used for a long time due to appearance of their side effects. As a result, we will use the medical treatment approach first before any invisible method if the case can be controlled with medications.
2. Endoscopic interventions

Sometimes we need to do what is called sphincterotomy which means using an endoscope to remove the sphincter that causes obstruction. However, this method is not effective in all types ofsphincters of Oddi dysfunction and should be used after medical treatment fails, as it may lead to complications of pancreatitis. 

• Studies show that in type I SOD- what is SOD? it will be effective to use sphincterotomy without doing a manometer as in this type there are features of biliary obstruction so no need to measure sphincter pressure. 
• But type II SOD studies found it should do manometry before doing sphincterometry as here treatment will be effective in patients with high sphincter pressure.
• In type III SOD we should use this approach with caution as it has more procedural risk with low beneficial outcomes.

Summary

We reach the end of our article and in the end don’t forget to go to your doctor if you feel abdominal pain without any reason as our disease is silent and rare, but your symptoms may be referred to as dysfunction in the sphincter of Oddi.  

FAQs

What causes sphincter oddi dysfunction?

The sphincter of oddi dysfunction is caused by spasms, strictures, scars, and relaxing the muscle valve which will lead to reflux of bile and pancreatic juices leading to abdominal pain.

What foods should be avoided with the sphincter of oddi?

Studies found that if you change your diet and start avoiding foods that trigger the sphincter of Oddi like chocolate, red meat, spicy food, alcohol, coffee, and fruits, especially acidic ones. That may help decrease pain and improve your health.

What is the best pain relief for the sphincter of oddi?

This includes several drugs that help decrease or suppress the pain like calcium channel blockers, Botox, somatostatin, and tricyclic antidepressants As found in a small study nifedipine can reduce pain by reverse opiate effect on the sphincter of Oddi. 

How do you fix a sphincter of oddi dysfunction?

You have three options to fix the sphincter depending on the patient's condition and the threat of pain they have

• Certain medication
• Sphinctectomy
• Botulinum toxin, which helps ease the symptoms 

How long do SOD attacks last?

The attack of pain may last 30 minutes to several hours, but pain may be mild and come and go fast or may be severe to wake people from sleep at night and may affect a person’s life.

What hormone relaxes the sphincter of oddi?

The hormone that helps the sphincter to relax is cholecystokinin hormone, which helps bile from the gallbladder to flow through the sphincter to the small intestine.