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HelpTest 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, FSpecimen Type
FecalOrdering 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.
Cautions
Bile acids are not stable in stool. Stool samples must be kept frozen immediately after collection.
Supportive Data
Bile acid (BA) malabsorption is suspected when total BA is greater than 2337 mcmol/48hr, or primary BA (% cholic acid plus chenodeoxycholic acid) is greater than 10%, or total BA is greater than 1000 mcmol/48hr + primary BA is greater or equal to 4%.(1)
Clinical Reference
1. Vijayvargiya P, Camilleri M, Chedid V, et al: Analysis of fecal primary bile acids detects increased stool weight and colonic transit in patients with chronic functional diarrhea. Clin Gastroenterol Hepatol. 2019;17(5):922-929.e2
2. Vijayvargiya P, Camilleri M, Current practice in the diagnosis of bile acid diarrhea. Gastroenterology. 2019;156:(5):1233-1238
3. Wedlake L, A'Hern R, Russell D, et al: Systematic review: The prevalence of idiopathic bile acid malabsorption as diagnosed by SeHCAT scanning in patients with diarrhoea-predominant irritable bowel syndrome. Aliment Pharmacol Ther. 2009;30:707-717
4. Shin A, Camilleri M, Vijayvargiya P, et al: Bowel functions, fecal unconjugated primary and secondary bile acids, and colonic transit in patients with irritable bowel syndrome. Clin Gastroenterol Hepatol. 2013 Oct;11(10):1270-1275
5. Longstreth GF, Thompson WG, Chey WD, et al: Functional bowel disorders. Gastroenterology. 2006;130:1480-1491
6. Camilleri M, McKinzie S, Busciglio I, et al: Prospective study of motor, sensory, psychologic, and autonomic functions in patients with irritable bowel syndrome. Clin Gastroenterol Hepatol. 2008;6:772-781
7. Vijayvargiya P, Camilleri M, Shin A, Saenger A: Methods for diagnosis of bile acid malabsorption in clinical practice. Clin Gastroenterol Hepatol. 2013 Oct;11(10):1232-1239
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)
Specimen Retention Time
7 daysPerforming 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)
Special Instructions
Forms
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.
Testing Algorithm
Secondary ID
607368Day(s) Performed
Wednesday