Inflammatory bowel disease (IBD) is a chronic gastrointestinal inflammatory condition commonly presenting in childhood; there are two main subtypes Crohn’s disease (CD) and ulcerative colitis (UC). Faecal Calprotectin (FCP) has been utilised as a marker of intestinal inflammation and has become routine in its use for management of IBD; both in monitoring disease activity and predicting relapse and remission in fluctuating pathology and symptomology of patients. This study aimed to assess the relationship between FCP, IBD activity indices and the commonly used blood markers in paediatric IBD.

In a retrospective data study at the Paediatric Gastroenterology Department at Hospital A, we analysed faecal calprotectin and disease activity using the scores Paediatric CD Activity Index (PCDAI) and Paediatric UC Activity Index (PUCAI) for Crohn’s Disease subtype and Ulcerative Colitis subtype respectively in 208 IBD patients from the years 2015 to 2021. Paris classification was used for phenotype identification. Spearman’s Rho correlation coefficient analysis was performed to draw and quantify correlation between faecal calprotectin and the two clinical scores.

208 patients were included in this study, with 115 CD (18% < 10 years and 82% 10–17 years) and 93 UC (32% < 10 years and 68% 10- 17 years). There was a positive correlation between FCP and PCDAI (r_­s = 0.546, p < 0.001) and between FCP and PUCAI (r­_s = 0.485, p < 0.001). FCP and activity indices were correlated positively with inflammatory markers/platelets and negatively with albumin and haemoglobin. FCP positively correlates with PCDAI in all CD phenotypes including isolated ileal disease.

In paediatric IBD, FCP appear to positively correlate with clinical picture and blood markers in all disease phenotypes and can provide an accurate non-invasive measure of disease activity.