• Diarrhoea-predominant IBS: chronic diarrhoea or IBS-D symptoms under practitioner review.
• Mixed-type IBS presentations: alternating diarrhoea and constipation in line with IBS-M patterns.
• Post-infectious IBS considerations: persistent gastrointestinal symptoms following food poisoning or acute gastroenteritis.
• Abdominal pain: cramping, discomfort or pain linked with bowel habit changes.
• Bloating and distension: frequent or unexplained bloating where post-infectious processes are suspected.
• Recurrent gastrointestinal symptoms: ongoing digestive disruption not explained by enteropathogen testing.
• Practitioners assessing IBS subtype: support for differentiating diarrhoeal or mixed presentations from constipation-predominant IBS.
• Clients with personal or family history of IBS: where stool-based or antibody-based review is clinically relevant.

IBS-smart is a plasma ELISA test measuring anti-CdtB and anti-vinculin antibodies, two biomarkers validated in research exploring post-infectious IBS, particularly IBS-D and IBS-M presentations. Results are displayed as elevated or not elevated against established reference intervals, helping practitioners understand how these markers appear at the time of sampling.

This assessment may be considered when practitioners are reviewing chronic diarrhoea, mixed bowel habits, abdominal pain, bloating, or symptom patterns emerging after a documented or suspected gastrointestinal infection. Anti-CdtB and anti-vinculin have been studied extensively in post-infectious IBS, with elevations reported in over 60 percent of IBS-D and IBS-M cases. Reviewing both markers together may help clarify whether an immune-mediated, post-infectious pattern could be contributing to the client’s presentation.

Practitioners typically interpret IBS-smart results in conjunction with symptom history, stool testing, dietary review and other functional assessments. Used in this way, it can support differential consideration of IBS-D and IBS-M patterns within a broader clinical context for clients.

This test requires a blood draw, so please ensure you can refer to a phlebotomist in the clients area before you order this test.

(Nordic Laboratories accept no cost or claims related to any phlebotomy services in the event of sample rejection or failure for any reason. By ordering this, or any test, requiring phlebotomy services, you accept any inherent risk and any associated costs.)

Sample Requirements:

Blood drawn (Lavender top K2 EDTA tube).

Plasma extracted and FROZEN.

Minimum 200 µL plasma.

Average processing time:

10-12 days

Morales, W., Rezaie, A., Barlow, G. et al. Second-Generation Biomarker Testing for Irritable Bowel Syndrome Using Plasma Anti-CdtB and Anti-Vinculin Levels. Dig Dis Sci 64, 3115–3121 (2019). https://doi.org/10.1007/s10620-019-05684-6

Lacy, Brian E. PhD, MD, FACG1; Pimentel, Mark MD, FACG2; Brenner, Darren M. MD, FACG3; Chey, William D. MD, FACG4; Keefer, Laurie A. PhD5; Long, Millie D. MDMPH, FACG (GRADE Methodologist)6; Moshiree, Baha MD, MSc, FACG7. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. The American Journal of Gastroenterology 116(1):p 17-44, January 2021. | DOI: 10.14309/ajg.0000000000001036