Diagnosis and inflammation

A noninvasive option to differentiate IBD and IBS

Patients with symptoms that arouse clinical suspicion of either inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS) are both common and tough to differentiate. However, because IBD and IBS are distinct conditions with contrasting treatment strategies, differentiating between the two is essential.

Calprotectin testing

Calprotectin, an indirect marker of intestinal inflammation, is a first-line testing option that can help differentiate between IBD and IBS. Furthermore, it may eliminate the need for additional invasive procedures or imaging studies, which are costly, involve sedation, and require patient compliance with fasting and bowel preparation.

Which test should I order?

Diagnosis of Crohn's disease and ulcerative colitis through serologic testing

Many commercial laboratories that do not treat patients advocate much wider application of laboratory testing, including serologic assessment, genetic testing, and inflammatory marker quantitation approaches. Peer-reviewed clinical literature only supports the use of three serologic tests for IBD and for limited applications.

Appropriate testing, guided by treatment

At Mayo Clinic, serologic testing for IBD is only used when a diagnosis of IBD has been made using modalities such as flexible sigmoidoscopy or colonoscopy with mucosal biopsies and radiographic studies, but where the results do not clearly differentiate between ulcerative colitis and Crohn’s disease.

Our serology panel, which is based on significant peer-reviewed literature, examines only the characteristic patterns of antibodies with demonstrated clinical utility:

  • Saccharomyces cerevisiae antibodies, IgA
  • Saccharomyces cerevisiae antibodies, IgG
  • Neutrophil specific antibodies (perinuclear anti-neutrophilic cytoplasmic antibody — pANCA)

Which test should I order?

IBDP | Inflammatory Bowel Disease Serology Panel, Serum

Note: due to a reagent issue, this test is currently unavailable for order

A focus on mucosal healing provides better outcomes

A focus on mucosal healing reduces the need for steroids and risk of hospitalization and surgery. Unfortunately, complete mucosal healing can be difficult to achieve, and agreement has not yet been reached over how much improvement is required for better outcomes.

However, a well-researched approach to mucosal healing improvements does exist. The CALM trial1 from 2018 found that an approach geared toward reducing inflammatory markers of calprotectin and serum CRP in addition to symptoms in patients with Crohn’s disease improved mucosal healing and led to better clinical and endoscopic outcomes than a conventional approach.

Benefits of this approach over other noninvasive tests for mucosal healing:

  • All markers are clinically actionable
  • More cost-effective than using larger panels
  • Validated in a peer-reviewed study

Learn more about how to order these evaluations at your institution.


1. Colombel JF, Panaccione R, Bossuyt P, et al. Effect of tight control management on Crohn’s disease (CALM): a multicentre, randomised, controlled phase 3 trial. Lancet. 2018 Dec 23;390(10114):2779-2789