Abstract Background Five-aminosalicylates (5ASAs) promote & maintain remission in people with ulcerative colitis (UC) and are administered orally or rectally, with combination therapy (oral + rectal) more effective than oral monotherapy, especially when treating flares1. 5ASAs may be perceived as out-dated and thus neglected. With increasing UC incidence & prevalence in emerging nations, understanding real-world 5ASA use and value is vital. Methods Crohn’s Colitis Care is a cloud-based electronic medical record used in Australasia. Data feed into a de-identified clinical quality registry (CQR), which was interrogated in September 2023. People with UC under active care (encounter within 14 months) were included. Results Of the 2,522 eligible people, 78.4% resided in Australia & 21.6% in New Zealand (NZ). The median age was 41 years (IQR 31-56), with an even gender distribution (50.3% female). Median disease duration was 9 years (IQR 4.4-16.7). Median duration of follow up was 25.9 months (IQR 13.0-41.4). Overall, 39.2% (n=989) had no documentation of 5ASA therapy (42.0% in Australia, 28.9% in NZ; Table 1). In those with documented 5ASA therapy (60.8%, n=1,534), the average 5ASA treatment duration was 9 years (IQR 4.4-16.7) and women were more likely to receive rectal administration than men (p<0.05). In those who ceased 5-ASA therapy, 782 (44.8%) had a reason documented, with the most common being medication rationalisation and/or deep remission (40.0%) (Figure 1), usually due to up-titration to a more advanced therapy. A total of 608 (39.6%) were recorded as already receiving additional IBD therapy at CQR entry (immunomodulators [IMs]/biologics/small molecules). Of those receiving 5ASAs alone at CQR entry (n=926), 5ASAs were subsequently judged to have failed in 37.8% (n=350). 5ASA failure was defined as the need for additional IBD therapies (99.1%, n=230 for IMs/biologics/small molecules and n=117 for steroids, total n=347); hospitalisation (n=3, 0.9%) or IBD surgery (n=0). Conclusion Despite not working for everyone, the long duration of 5ASA therapy indicates they are well tolerated & perceived as beneficial by consumers. There was greater 5ASA utilisation in NZ, possibly due to restricted advanced therapy access. Gender-specific trends in 5ASA administration were identified, raising the question as to why this should be so, given this is not obviously explained by disease phenotype. Further analysis is needed to tease out how such trends interact with other therapeutic access, choices and outcomes. 1 - Probert C et a. Combined oral and rectal mesalazine for the treatment of mild-to-moderately active ulcerative colitis: rapid symptom resolution and improvements in quality of life. J Crohns Colitis. doi:10.1016/j.crohns.2013.08.007