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Test Code BA48F Bile Acids, Bowel Dysfunction, 48 Hour, Feces

Useful For

Aids to evaluate patients suspected of having irritable bowel syndrome-diarrhea (IBS-D) symptoms due to bile acid malabsorption

Reporting Name

Bile Acids, Bowel Dysfunc, 48 Hr, F

Specimen Type

Fecal


Ordering Guidance


This test is for evaluation of bowel dysfunction.

 

For evaluation of hepatobiliary dysfunction, order BILEA / Bile Acids, Total, Serum.

For evaluation of patients treated with urso or cholate, order BAFS / Bile Acids, Fractionated and Total, Serum.

For evaluation of inborn errors of metabolism, order BAIPD / Bile Acids for Peroxisomal Disorders, Serum.



Specimen Required


Patient Preparation:

For 3 days prior to and during the collection period:

1. Patient should be on a fat-controlled diet (100-150 g fat per day)

2. No laxatives (particularly mineral oil and castor oil)

3. No synthetic fat substitutes (eg, Olestra) or fat-blocking nutritional supplements

Supplies: Stool Containers - 24, 48, 72 Hours Kit (T291)

Collection Container/Tube: Stool container (T291); complies with shipping requirements, do not use other containers

Specimen Volume: Entire 48-hour collection

Collection Instructions:

1. Do not use other containers.

2. All containers must be sent together.

3. The entire collection must contain at least 5 g of feces.

4. The number of containers sent should be indicated on the labels (1 of 4, for example).

Additional Information:

1. Patient may store sample at refrigerate temperature during collection period.

2. Barium interferes with test procedure; a waiting period of 48 hours before stool collection analysis is recommended.


Specimen Minimum Volume

5 g

Specimen Stability Information

Specimen Type Temperature Time Special Container
Fecal Frozen 30 days

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

Bile acids are natural products of cholesterol synthesis that aid in the emulsification and absorption of dietary fats in the small intestine. The majority of bile acids are reabsorbed in the ileum of the healthy individual, with only 5% excreted in feces.(1) Primary bile acids cholic acid (CA) and chenodeoxycholic acid (CDCA) are deconjugated and dehydroxylated via intestinal bacteria into secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA), respectively.(2) The sum of CA, CDCA, DCA, LCA, and ursodeoxycholic acid (UDCA) compose the majority of bile acids in the feces. Impaired absorption of bile acids in the terminal ileum leads to excess bile acids in the colon that can cause diarrhea from chloride and water secretion; a condition called bile acid malabsorption (BAM).

 

Irritable bowel syndrome (IBS) is a nonspecific multifactorial disorder involving the large intestine. IBS is characterized by cramping, bloating, diarrhea, and constipation and classified as either IBS-D (diarrhea) or IBS-C (constipation) by the Rome III criteria.(3) Up to 50% of IBS-D patients have accelerated colonic transit time; the mechanism of IBS-D pathophysiology is varied with more than 25% having BAM.(1,4)

 

Several methods have been developed for detection of BAM, but are not widely available in clinical practice.(5) Therefore, patients are often placed on trials of bile acids sequestrants to determine if symptoms improve.

 

Quantitation of fecal bile acids aids in screening for IBS-D and identification of patients with chronic diarrhea who may benefit from bile acid sequestrant therapy.

Reference Values

≥ to 18 years:

Sum of cholic acid and chenodeoxycholic acid ≤9.7%

Total bile acids ≤2619 mcmoles/48 hours

 

Reference values have not been established for patients who are <18 years of age

Interpretation

Elevated total fecal bile acid or percent cholic acid plus chenodeoxycholic acid is consistent with the diagnosis of bile acid malabsorption.

 

Pharmacological treatment with bile acid sequestrants has been shown to improve symptoms in some patients.

Method Description

Fractionated fecal bile acids are quantified in a 48-hour fecal collection during which a high-fat intake diet was followed. Samples are analyzed on a tandem mass spectrometer.(Unpublished Mayo method)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BA48F Bile Acids, Bowel Dysfunc, 48 Hr, F 93338-2

 

Result ID Test Result Name Result LOINC Value
36968 Bile Acids, % CDCA + CA, F 93337-4
36969 Total Bile Acids, F 93336-6
610285 Stool Weight 30078-0

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Forms

If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.

Secondary ID

607368

Day(s) Performed

Wednesday