Inflammatory Bowel Disease Outcomes in Northern Iran: A Retrospective Cohort Study of Remission, Complications, and Treatment Strategies.

Background: Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory condition affecting the gastrointestinal tract. While significant progress has been made in managing IBD, the long-term outcomes remain heterogeneous, prompting this cohort study. Methods: A retrospective analysis was performed on patients with IBD registered between 2000 and 2023. Clinical data, including demographics, disease activity, remission rates, therapeutic approaches, and complications, were collected. Results: Among 600 enrolled patients, 72.8% were diagnosed with UC. Both patients with UC and those with CD showed improvements in endoscopic severity by the end of follow-up (p < 0.001). Clinical remission was achieved by 96.3% of patients with UC and 91.2% of those with CD during the last 6 months of follow-up (p = 0.046). Disease progression occurred in 22.1% of patients with CD and 18% of those with UC (p = 0.100). Gastrointestinal complications were more prevalent in patients with CD (25.6% vs. 1.6%, p < 0.001). Relapse remained high, with 86.7% of patients with UC and 92.6% of those with CD experiencing relapses at least once during follow-up, particularly those with severe baseline disease (p < 0.01). Biologic therapies were used more frequently (p < 0.01) and initiated earlier in patients with CD (p = 0.031). Conclusion: The study showed significant clinical improvement, yet many patients, particularly those with severe initial disease, had incomplete remission and frequent relapses, necessitating more effective long-term management strategies. The distinction between CD and UC highlights the need for specialized treatments.