Biliary dyskinesia overview

# Overview
Biliary Dyskinesia develops when there is a bile stasis in the absence of any mechanical obstruction. There is a dynamical obstruction rather than fixed mechanical obstruction. In this condition, bile can not be properly propelled from the gall bladder or can not properly flow out of the end of common bile duct. The motility disorders of functional gallbladder disorder (FGD) and sphincter of Oddi disorder (SOD), cause biliary colic in the absence of gallstones. The pain is usually crampy and in the right upper quadrant (RUQ) about 30 minutes after a meal. Other symptoms include intolerance to fatty food, bloating, nausea and vomiting. The Rome IV diagnostic criteria should be considered in patients with biliary pain and suspected motility disorders (functional gallbladder disorder and functional biliary sphincter of Oddi disorder). HIDA scan with an abnormal gallbladder ejection fraction (<40%) is a supportive criteria for diagnosing biliary dyskinesia but is not required for the diagnosis anymore. Sphincter of Oddi manometry may be used to rule out functional biliary sphincter of Oddi disorder (SOD) in patients who have had a cholecystectomy. Laparoscopic cholecystectomy is used to treat biliary dyskinesia and endoscopic biliary sphincterotomy is performed in patients with sphincter of Oddi disorder (SOD) diagnosed by manometry.

# Pathophysiology
The exact pathophysiology of biliary dyskinesia is unknown. However, there have been some suggestions as the causes of biliary dyskinesia such as the following: the biliary pain in gallbladder dyskinesia may be the result of gallbladder inflammation due ineffective gallbladder contraction caused by gallbladder dysmotility,  visceral hypersensitivity, and receptor or neurologic abnormalities. Consequently, abnormality in gallbladder or sphincter of Oddi contraction results in inflammation and biliary pain.

# Causes
The following motility disorders cause biliary colic without the presence of gallstones: functional gallbladder disorder (FGD) and biliary sphincter of Oddi disorder (SOD).

# Differentiating Biliary dyskinesia from other Diseases
Biliary dyskinesia should be differentiated from other disorders that caused right upper quadrant (RUQ) pain, such as abdominal disorders with pain similar to biliary pain, peptic ulcer disease (PUD), gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), coronary artery disease, costochondritis, and musculoskeletal disorder. 

# Epidemiology and Demographics
The incidence of cholecystectomy procedure for biliary dyskinesia has been reported to be 85 cases per million individuals in the United States and about 25 cases per million individuals outside the United States. The prevalence of functional gallbladder disorder (FGD) and sphincter of Oddi disorder (SOD) is unknown.

# Natural History and Prognosis
Symptoms of biliary dyskinesia have been reported to resolve without any invasive procedure in about half of the patients. Patients with gallbladder dyskinesia (GD) that have typical classic biliary symptoms are more likely to have improvement after cholecystectomy compared to those with atypical symptoms. Relief of symptoms has been reported in 80% of the patients that were diagnosed with sphincter of Oddi disorder (SOD) by manometry and treated with sphincterotomy.

# Diagnosis

## Diagnostic Criteria
The Rome IV diagnostic criteria should be considered in patients with biliary pain and suspected motility disorders (functional gallbladder disorder and functional biliary sphincter of Oddi disorder).

## History and Symptoms
In order to exclude other disorders, the patient's history is important in the diagnosis of biliary dyskinesia. Symptoms of biliary dyskinesia are characterized by biliary colic symptoms and include: postprandial pain in the right upper quadrant (RUQ) (that radiate to the flank, back, and right scapula), intolerance to fatty food, pain in the evening or awaking the patient at night, bloating, nausea and vomiting.

## Physical Examination
Symptoms of biliary dyskinesia are characterized by biliary colic symptoms. The following clinical presentations are not likely due to functional biliary disorder: positive Murphys sign, constant abdominal pain without tenderness, jaundice, and intermittent abdominal pain and cramps with episodes of diarrhea or constipation. 

## Laboratory Findings
The initial laboratory work-up should include: liver function tests (AST, ALT, and total bilirubin), amylase, and lipase.

## CT
CT scan is not helpful in diagnosing gallbladder or biliary diseases.

## Ultrasound
Ultrasound is required in these patients in order to exclude structural conditions such as gallstone disease or cancer. Ultrasound may be used in order to diagnose sphincter of oddi disorders (SOD) by measuring the common bile duct (CBD) diameter.

## Other Imaging Findings
Hepatobiliary iminodiacetic acid (HIDA) with an abnormal gallbladder ejection fraction (<40%) is a supportive criteria for diagnosing biliary dyskinesia but is not required for the diagnosis anymore. Noninvasive procedures that may be used to evaluate and diagnose  sphincter of Oddi disorders (SOD) are: ultrasound, HIDA scan, and MRCP.

## Other Diagnostic Studies
ERCP and sphincter of Oddi manometry may be used to rule out functional biliary sphincter of Oddi disorder (SOD) in patients who have had a cholecystectomy.  Although sphincter of Oddi  manometry is the diagnostic tool for evaluating  sphincter of Oddi disorders (SOD), it is an invasive procedure and has risk for complications.

# Treatment

## Medical Therapy
Medical therapy mostly includes of symptomatic treatment of abdominal pain and IV opiates are the drug of choice, although some studies have suggested that opiates cause sphincter of Oddi  contraction.

## Surgery
Laparoscopic cholecystectomy is used to treat biliary dyskinesia. Endoscopic biliary sphincterotomy is performed in patients with sphincter of Oddi disorder (SOD) diagnosed by manometry.

## Cost-Effectiveness of Therapy
There is insufficient evidence about the cost-effectiveness of therapy in biliary dyskinesia.

## Future or Investigational Therapies
Further studies are required to assess the outcome of surgical (cholecystectomy) versus nonsurgical treatments (those used in treatment of other functional disorders) in bilary dyskinesia.