ALB and irritable bowel syndrome: The calculation of NPV in diagnosing IBD was found to be the highest at 96.0% when the FC threshold was set at 200 μg/g or low albumin was present (i.e., if one has FC <200 μg/g and normal albumin level, there is 96.0% (95% CI 80.5–99.8%) probability the child does not have IBD) (Supplementary Table 1).