On further physician chart review, 6 of the 8 participants with IBD–IBS overlap had evidence of mild abnormalities on laboratory testing (as defined by fecal calprotectin <100 μg g−1,36 erythrocyte sedimentation rate <8 mg L−1, C-reactive protein <2.9 mm hr−1), radiologic imaging (computed tomography or magnetic resonance enterography), or endoscopic evaluation within 90 days of this research encounter. This evidence concerns the gene CRP and irritable bowel syndrome.