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Introduction There is limited evidence to support assessing patients with irritable bowel syndrome (IBS)-type symptoms for underlying pancreatic exocrine insufficiency (PEI). Patients with a low faecal elastase-1 (FE-1) may derive symptomatic benefit from pancreatic enzyme replacement therapy (PERT), even in those with minimal or no radiological morphological pancreatic disease. Furthermore, this removes this sub-group of patients from those with actual IBS, which may make pharmacological treatments more effective in the remaining IBS cohort. We aimed to determine the prevalence of low FE-1 as a marker of PEI and assess response to PERT in a dual-centre functional gastrointestinal (GI) cohort.Methods A retrospective dual-centre service evaluation was performed in patients with IBS-type symptoms attending general gastroenterology clinics. Patients underwent FE-1 testing between 2018–2023 at one centre and 2022–2024 at the other. Patients with known pancreatic disease, established organic GI pathology, or red-flag features were excluded. PEI was defined as FE-1 <200 µg/g, with severe PEI <100 µg/g. Clinical data were extracted from electronic health records, and associations were assessed using chi-squared or Fisher’s exact tests.Results A total of 999 patients underwent FE-1 testing (median age 56 [IQR 42–67]; 58.5% female). Low FE-1 (<200 µg/g) was identified in 88 patients (8.8%), including 35 (3.5%) with FE-1 <100 µg/g. Severe PEI was more common in males (5.3% vs 2.2%; OR 2.46; p=0.01). Increasing age was associated with low FE-1; for every 10-year increase in age, the odds of a low FE-1 increased by ~19% (OR 1.19 per decade; p=0.01). No specific individual GI symptoms were associated with low FE-1 at either threshold. Diabetes mellitus (type 1 & 2) was associated with low FE-1 (<200 µg/g) (OR 2.62; p<0.001).Among patients with FE-1 <200 µg/g, 75/88 (85.2%) received a diagnosis of PEI, of whom 73/75 (97.3%) received PERT. Follow-up data were available for 46/73 (63.0%). Of these, symptomatic improvement was documented in 34/46 (73.9%), including complete resolution in 7/46 (15.2%).Repeat FE-1 testing was performed in 37 patients. Diagnostic reclassification (FE-1 <200 vs ≥200 µg/g) occurred in 6/37 (16.2%) (3/37 normalised and 3/37 became abnormal). The majority, 30/37 (81.1%), remained within the same FE-1 category (<100, 100–199, ≥200 µg/g).Conclusion The prevalence of PEI in adults with IBS-type symptoms was 8.8%. Despite recognised limitations of false-positive FE-1 testing, a substantial proportion of patients with low FE-1 appear to derive symptomatic benefit from PERT. In selected patients, low FE-1 may represent early or subclinical pancreatic dysfunction and could be considered as part of the diagnostic work-up, alongside further pancreatic evaluation including cross-sectional imaging and nutritional assessment.