A simple way to diagnose IBS vs. IBD

Sep 15, 2015 - E-Mentoring in IBD | Volume 08 • 2015

Issue 18

Clinical Question

For patients presenting with irritable bowel syndrome (IBS)-like symptoms and no alarm features, is it possible to make a confident diagnosis of IBS versus inflammatory bowel disease (IBD) without a battery of tests?

Editor’s Bottom Line

– A C-reactive protein level of ≤0.5 µg/g or a fecal calprotectin level of ≤40 µg/g indicates that the person has a ≤1% probability of having IBD

– A good history and these two tests are all that should be required to confirm the IBS diagnosis.


Menees SB, Powell C, Kurlander J, et al. A meta-analysis of the utility of C-reactive protein, erythrocyte sedimentation rate, fecal calprotectin, and fecal lactoferrin to exclude inflammatory bowel disease in adults with IBS. Am J Gastroenterol. 2015 Mar;110(3):444–54.  https://www.ncbi.nlm.nih.gov/pubmed/25732419


In this meta-analysis, only prospective diagnostic studies involving the use of C-reactive protein, erythrocyte sedimentation rate, fecal calprotectin (ELISA), and fecal lactoferrin for the diagnosis of IBS were included. Patients with IBD had a confirmed diagnosis. The meta-analysis considered three cohorts: IBD, IBS, and healthy controls. Data analysis using (Bayes’ theorem) estimated the probabilities of biomarker levels and if the individual had IBD, IBS, or was a healthy control.

Data collected from 12 studies identified that none of the biomarkers could discriminate between a healthy individual compared with someone experiencing IBS-like symptoms. However, a C-reactive protein level of ≤0.5 µg/g or a fecal calprotectin level that was ≤40 µg/g indicated that the person had a ≤1% probability of having IBD.

Both erythrocyte sedimentation and lactoferrin were not able to distinguish between the three types of cohorts.


Study Design: Meta-analysis
Funding: University of Michigan Health System
Allocation: N/A
Setting: N/A
Level of Evidence: 1a (Oxford Levels of Evidence)

The summary and conclusion in this issue of E-mentoring in IBD pertains to the manuscript(s) being reviewed, and should be considered in the context of what is already known surrounding the topic and incorporated into practice as deemed appropriate by the individual learner.