Background:Digital chromoendoscopy with magnification is a technique that identify microscopic inflammation, with a better characterize, highlighting specific gastrointestinal findings showing a good correlation with histopathological features. Spondyloarthritis (SpA) patients with the presence of non-specific gastrointestinal symptoms, subclinical intestinal inflammation is defined by endoscopic and histological techniquesObjectives:To detect early structural inflammatory changes by chromoendoscopy and magnification colonoscopy in colonic/ileum digestive mucosa and establish its association with clinical variables in patients with SpA and gastrointestinal symptomsMethods:In total, 180 patients with SpA (ASAS/criteria) were assessed by rheumatologists, of which (n=35) (19.4%) had an indication by a gastroenterologist to perform the chromoendoscopy, magnification colonoscopy and histological analysis. The association between clinical and colonoscopy variables were evaluated using the Chi square or Fisher’s exact test. (Ethical/Code. 2017-023)Results:The average age of the patients included for colonoscopy was 45.4±10.3 years, 57.1% were men and 42.9% presented the HLA-B*27 allele. Axial involvement (91.4%), inflammatory back pain (68.6%) and use of biological therapy (71.4%). High levels of calprotectin (25.7%), CRP>3 (14.3%), positive ESR (22.9%) and positive ANCA (8.6%) was observed. Regarding outcome measures of function and activity, BASDAI >4 (60%) and ASDAS-PCR >2.1 (80.0%) was observedThe loss of vascular pattern in the ileum was associated with high levels of calprotectin levels (p=0.002). At microscopic level, 80% of the patients who presented acute inflammation in the ileum had elevated calprotectin (p=0.013). Cryptitis (77.8%) in the ileum was associated with axial involvement (p=0.017). Ulcers and erosion in the ileum were associated with positive ESR (p=0.003). All patients who presented ulcerations and inflammation (64.3%) in ileum were HLA-B27 positive (p=0.029) and (p=0.052) respectively. The 50% of patients with atrophy of villi in ileum were receiving biological treatment (p=0.035)Conclusion:Digital chromoendoscopy and augmentation colonoscopy provided an improved and detailed contrast of the surface of the gastrointestinal mucosa. The tissue sampling showed the loss of vascular pattern as main finding in ileum with interesting associations with fecal calprotectin levels in patients with SpA. The interest of proposing the active search for symptoms, signs and biomarkers of gastrointestinal involvement in patients with SpA without IBD is to define subclinical gastrointestinal involvement and early remission through an endoscopic evaluation and objective histological and propose a specific clinical and therapeutic treatment.Acknowledgments:The Government Institute of Science, Technology, and Innovation, Francisco Jose de Caldas—COLCIENCIAS(Grant No. 130877757442). Universidad El Bosque (PCI-2018-10091), Hospital Militar Central (Grant 2017-023), Clínicos IPS, Gastroadvanced, Fundación Instituto de Reumatología Fernando Chalem-Bogota, Colombia and Biomedicina de Chihuahua, MéxicoDisclosure of Interests:None declared

There is little literature on the implementation of screening criteria for inflammatory bowel disease (IBD) in patients with spondyloarthritis (SpA). This study aimed to apply IBD screening criteria in a group of patients with SpA without IBD diagnosis and correlate them to endoscopic findings and disease activity. A total of 82 patients with SpA were included. The IBD screening test and ileocolonoscopy with digital chromoendoscopy with magnification and histological analysis were performed. The data were analysed with Chi-square test/Fisher’s exact test and multiple correspondence analysis. The major screening criteria found in 48.7% of the patients were associated with a history of infection (p = 0.037). Rectal bleeding was associated with the diagnosis of ankylosing spondylitis, acute inflammation, enthesitis and tissue architecture alteration in the ileum (p < 0.050). Diarrhoea was associated with a higher disease activity score (p = 0.02). Minor screening criteria were associated with painful inflammatory joint (p = 0.05), high disease activity score (p = 0.001) and high calprotectin levels (p = 0.050). Abdominal pain (36.9%) was associated with axial/peripheral compromise (p = 0.017), inflammatory back pain (p = 0.01), enthesitis (p = 0.021), higher disease activity score (p = 0.023) and acute ileum inflammation (p = 0.046). Diarrhoea of 4 weeks and abdominal pain were the most prevalent major and minor screening criteria, respectively, being related to early manifestations of inflammatory bowel compromise and higher disease activity score. This screening test grants a chance of opportune referral of SpA patients from rheumatology to gastroenterology.