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Introduction Quantitative faecal immunochemical testing (FIT) is widely used to triage individuals with lower gastrointestinal (GI) symptoms. Locally, faecal haemoglobin (f-Hb) >400 µg/g is used as a prioritisation threshold for urgent investigation. We aimed to review symptomatic FIT requesting and result patterns in NHS Tayside, with a specific focus on investigations and diagnoses in individuals with f-Hb >400 µg/g.Methods We performed a retrospective observational audit of all NHS Tayside FIT requests between 1 Jan 2016 and 31 Dec 2023. Buffered samples were analysed (HM-JACKarc) in a UKAS-accredited laboratory. Results were extracted from the laboratory data system along with basic demographic information. Deprivation was assessed using the Scottish Index of Multiple Deprivation, 2020 (SIMD). Sub-group analyses were performed on individuals with index f-Hb >400 µg/g across two years, 2016 and 2022. Electronic case note review captured investigations, time to investigation, and diagnostic outcome. These were compared between years using Chi-square, Wilcoxon and two-proportion z-test. The primary outcome was significant bowel disease (SBD), defined as colorectal cancer (CRC), inflammatory bowel disease (IBD), or high-risk polyps (HRP). Additionally, multivariable logistic regression was used to identify factors associated with invalid samples.Results In total, 101,358 FIT requests were received from 72,385 individuals (58.2% female, median age 64 years). Requesting increased throughout the period (2016, n=5,812; 2023, n=18,534). Overall, 1.5% of samples were invalid. These were associated with older age (odds ratio [OR] 1.03 per year) and higher deprivation (SIMD 1–2 vs. 3–5, OR 1.71). Among 99,846 valid results, overall positivity (f-Hb ≥10 µg/g) was stable at 22.2%. Results >400 µg/g fell from 5.3% (n=302) in 2016 to 4.2% (n=798) in 2023 (p<0.001). The proportions of individuals referred (94.4% vs. 88.8%, p=0.008) and undergoing any lower GI investigation (87.7% vs. 81.8%, p=0.023) were lower in 2022, compared with 2016. Median time to colonoscopy increased from 31.5 to 35 days (p=0.004). The yield of SBD decreased (45.7% vs. 34.5%, p=0.002), largely due to fewer CRC diagnoses (22.6% vs. 14.1%, p=0.002), whereas IBD remained stable [ figure 1].Conclusions Symptomatic FIT use in NHS Tayside tripled between 2016 and 2023 but positivity remained static (22.2%). Among patients with f-Hb >400 µg/g, data from 2016 and 2022 indicate reduced yield of SBD, particularly CRC. Increased demand for colonoscopy is resulting in longer waiting times. These data demonstrate the need to optimise FIT demand and interpretation within referral pathways, including those patients with very high f-Hb.Abstract P320 Figure 1Comparison of yield of significant bowel disease at investigation (2016 vs. 2022)