Academy of Medical Sciences of I.R. Iran Archives of Iranian Medicine 1029-2977 27 4 2024 04 01 Clinical Phenotype and Disease Course of Inflammatory Bowel Disease in Iran: Results of the Iranian Registry of Crohn’s and Colitis (IRCC) 183 190 10.34172/aim.2024.27 EN Bahar Saberzadeh-Ardestani https://orcid.org/0000-0002-7244-1839 Amir Ali Khosravi Fariborz Mansour-Ghanaei Homayoon Vahedi Nadieh Baniasadi Mohammadreza Seyyedmajidi Baran Parhizkar Ahmad Hormati Sayed Jalalledin Naghshbandi Somaieh Matin Amir Abbas Hassan Zadeh Tarang Taghvaei Mohsen Bahrami Mandana Rafeey Mitra Ahadi Hassan Vossoughinia Hashem Muosavi Shahsanam Gheibi Roya-Sadat Hosseini-Hemmatabadi Abbas Yazdanbod Saied Matinkhah Farshad Sheikh Esmaeili Hafez Fakheri Seyed Hamid Moosavy Iradj Maleki Siavosh Nasseri-Moghaddam Bardia Khosravi Fatemeh Farahmand Mehri Najafi Hosein Alimadadi Masoud Malekzadeh Amir Anushiravani Amir Kasaeian https://orcid.org/0000-0003-2018-9368 Sudabeh Alatab Anahita Sadeghi Amir Reza Radmard Shadi Kolahdoozan Zeynab Rajabi Ali Reza Sima https://orcid.org/0000-0002-1397-4846 Journal Article 10.34172/aim.2024.27 2024 01 04 2024 02 19 Background: Data on the epidemiology of inflammatory bowel disease (IBD) in the Middle East are scarce. We aimed to describe the clinical phenotype, disease course, and medication usage of IBD cases from Iran in the Middle East. Methods: We conducted a cross-sectional study of registered IBD patients in the Iranian Registry of Crohn’s and Colitis (IRCC) from 2017 until 2022. We collected information on demographic characteristics, past medical history, family history, disease extent and location, extra-intestinal manifestations, IBD medications, and activity using the IBD-control-8 questionnaire and the Manitoba IBD index, admissions history, history of colon cancer, and IBD-related surgeries. Results: In total, 9746 patients with ulcerative colitis (UC) (n=7793), and Crohn’s disease (CD) (n=1953) were reported. The UC to CD ratio was 3.99. The median age at diagnosis was 29.2 (IQR: 22.6,37.6) and 27.6 (IQR: 20.6,37.6) for patients with UC and CD, respectively. The male-to-female ratio was 1.28 in CD patients. A positive family history was observed in 17.9% of UC patients. The majority of UC patients had pancolitis (47%). Ileocolonic involvement was the most common type of involvement in CD patients (43.7%), and the prevalence of stricturing behavior was 4.6%. A prevalence of 0.3% was observed for colorectal cancer among patients with UC. Moreover,15.2% of UC patients and 38.4% of CD patients had been treated with anti-tumor necrosis factor (anti-TNF). Conclusion: In this national registry-based study, there are significant differences in some clinical phenotypes such as the prevalence of extra-intestinal manifestations and treatment strategies such as biological use in different geographical locations.