BACKGROUND: Acid reflux is a common presentation in primary care leading to a high volume of referrals to endoscopy that are often normal. AIMS: To determine whether a non-endoscopic capsule sponge biomarker test could triage patients with low-risk reflux symptoms, reduce endoscopy waiting lists and identify Barrett's oesophagus in a real-world setting. METHODS: Patients with reflux symptoms on NHS endoscopy waiting lists who were offered a capsule sponge (test group) between February 2021 and August 2022 were included in this national multicentre prospective cohort study and compared with eligible patients on the standard endoscopy pathway (counterfactual group). RESULTS: Two thousand one hundred seventy patients from 23 hospitals undertook a capsule sponge triage test and submitted follow-up data, of whom 1694 (78%) were discharged without endoscopy and 476 (22%) were referred for endoscopy. In a detailed subgroup analysis 1411/1549 (92%) attended and successfully swallowed the capsule of whom 307/1411 (21.8%) required endoscopy. Of 111 patients with positive capsule sponge biomarker results who had endoscopy, 19.8% had Barrett's oesophagus. In comparison, in patients with negative sponge biomarkers who were referred for endoscopy due to ongoing symptoms, none had Barrett's oesophagus (p = 0.0002). Eighty-two percent surveyed (267/357) were satisfied with the alternative pathway. CONCLUSIONS: Capsule sponge triage is feasible, safe and acceptable. It substantially reduces the endoscopy burden for routine reflux referrals with a favourable diagnostic yield for Barrett's oesophagus. Longer term follow-up will help to confidently assess the impact of the programme and place of capsule sponge in the diagnostic pathway.