Simplifying the Diagnosis of Bile Acid Malabsorption: Fasting Serum C4 and Proportion of Primary Bile Acids Measured from a Random, Single Stool Sample

Overview

About this study

We aim to validate fasting serum C4 and primary bile acids from a single stool sample (individually or in combination) in 65 patients with diarrhea predominant irritable bowel syndrome (IBS-D), 30 healthy volunteers, and 12 patients with terminal ileal resection > 10 cm. First, we will validate the combined serum C4 and primary bile acids in patients with IBS-D without BAM, IBS-D with BAM, and healthy volunteers by comparing the individual or combined serum and stool test to documented 48 hour total fecal bile acid (current gold standard to diagnose bile acid malabsorption in the USA). Second, we will evaluate the utility of combined serum and blood test in patients with ileal resection > 10 cm, compared to data prospectively collected from healthy volunteers.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria

Healthy volunteers - All participants will complete a validated bowel disease questionnaire

  • HAD: No restrictions on Hospital Anxiety/Depression score.
  • Age: 18-75 years
  • Gender: Men or women. Ratio of 5 female to 1 male expected. Lactating and women are eligible. Women of childbearing potential will have a negative pregnancy test before initiation of the study. 
  • Previous 48 hour fecal bile acid test measurement in either the clinical or research setting or previous fasting serum C4 measurement >52ng/mL. If no previous 48 hour total fecal bile acids were collected in the past, the participant will be asked to complete one during the study

IBS-D or chronic diarrhea- All participants will complete a validated bowel disease questionnaire

  • BDQ- IBS symptoms: Positive by Rome IV criteria
  • HAD: No restrictions on Hospital Anxiety/Depression score.
  • Age: 18-75 years
  • Gender: Men or women. Ratio of 5 female to 1 male expected. Lactating and women are eligible. Women of childbearing potential will have a negative pregnancy test before initiation of the study.  
  • Previous 48 hour fecal bile acid test measurement in either the clinical or research setting or previous fasting serum C4 measurement >52ng/mL. If no previous 48 hour total fecal bile acids were collected in the past, the participant will be asked to complete one during the study

Ileal resection >10 cm - All participants will complete a validated bowel disease questionnaire

  • HAD: No restrictions on Hospital Anxiety/Depression score.  
  • Age: 18-75 years
  • Gender: Men or women. Lactating and women are eligible. Women of childbearing potential will have a negative pregnancy test before initiation of the study. 

Exclusion criteria for IBS-D, chronic diarrhea and healthy volunteers

  • Use of drugs or agents within the past 1 week or during the study period (birth control pill, estrogen replacement therapy, metformin and thyroxine replacement are permissible exceptions, hypertension agents, SSRI, SNRI):
    • Agents that alter GI transit including opioids, narcotics, anticholinergics, tricyclic antidepressants, SNRI antidepressants.
    • Analgesic drugs including opiates, NSAID, COX 2 inhibitors
    • Intake of medication that could interfere with the interpretation of the study. 
  • Abdominal surgery (except appendectomy, hernia repairs and cholecystectomy); specifically, prior gastric surgery, vagotomy, cholecystectomy and any small bowel resection will be excluded.
  • Female patients who are pregnant (in view of the changes in hepatic metabolism or cholestasis that may occur during pregnancy)
  • Patients with known chronic liver disease or history of elevated AST/ALT 2.0 X ULN
  • BA synthesis and possible false positive or negative fecal bile acid or serum 7alphaC4 result.no AST or ALT values in the medical record, the study physicians will determine if the tests need to be run.

Exclusion criteria for patients with ileal resection

The same as above except:   

  • Abdominal surgery (except ileal resection, appendectomy, hernia repairs and cholecystectomy); specifically, prior gastric surgery, vagotomy, cholecystectomy and any colon resection will be excluded.

 

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Michael Camilleri, M.D.

Open for enrollment

Contact information:

Sara Linker Nord CCRP

(507)266-1999

LinkerNord.Sara@mayo.edu

More information

Publications

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Study Results Summary

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Supplemental Study Information

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