Risk factors for clinical relapse in patients with ulcerative colitis who are in clinical remission but with endoscopic activity

Background and Aim The treatment strategy for patients with ulcerative colitis (UC) in clinical remission who have not achieved mucosal healing is unclear. This study aimed to determine the risk factors of relapse in patients in clinical remission with endoscopic activity. Methods This retrospective, single‐center study included patients with UC who underwent colonoscopy (CS) and were in clinical remission with endoscopic activity. Characteristics were compared between patients who relapsed within 2 years after CS and those who did not. A Cox proportional hazards regression model was used to identify risk factors contributing to clinical relapse. Recent worsening in bowel symptoms was defined as increase in bowel frequency and/or increase in abdominal pain within approximately 1 month based on the descriptions in the medical charts. Results This study regarded 142 patients in clinical remission with an endoscopic activity of Mayo endoscopic subscore (MES) of ≥1 as eligible, and 33 (23%) patients relapsed during the observation period. Recent worsening of bowel symptoms was a significant risk factor for clinical relapse (hazard ratio [HR]: 3.02, 95% confidence interval [CI]: 1.34–6.84). This was particularly evident in patients with MES of 2 (HR: 5.16, 95% CI: 1.48–18.04), whereas no risk factors were identified in patients with MES of 1. The presence or absence of therapeutic intervention just after CS did not significantly affect clinical relapse. Conclusion Recent worsening in bowel symptoms was a significant risk factor for clinical relapse in patients with UC who were in clinical remission with endoscopic activity. This study revealed that recent worsening in bowel symptoms was a significant risk factor for clinical relapse in ulcerative colitis [UC] patients in clinical remission but without mucosal healing. This trend is particularly evident in patients with higher endoscopic activity (Mayo endoscopic subscore [MES] of 2) but not in those with lower endoscopic activity (MES of 1). Therefore, patients in clinical remission should be thoroughly interviewed for symptoms and therapeutic intervention should be cautiously considered for those with endoscopic activity.