Bowel Urgency Is More Strongly Associated with Biochemical, Endoscopic, and Histological Disease Activity than Other Clinical Symptoms in Ulcerative Colitis.

Objective　Bowel urgency (BU) is one of the most common and distressing symptoms of ulcerative colitis (UC). However, its relationship with the disease activity has not yet been fully elucidated. We aimed to evaluate the clinical significance of BU as an indicator of the disease activity in comparison with other clinical symptoms of UC.Methods　We conducted a retrospective observational study of patients with UC who underwent colonoscopy at our institution. Correlation analyses were performed between symptomatic subscores, including BU, stool frequency, rectal bleeding, and physician's global assessment, and the disease activity indices. The BU subscore was assessed using the BU item of the Simple Clinical Colitis Activity Index (SCCAI) without modification, as follows: 0, no BU; 1, acute BU; 2, immediate BU; and 3, stool incontinence. In addition, the clinical disease activity (Mayo and partial Mayo scores), biochemical markers, endoscopic activity (Mayo Endoscopic Subscore [MES] and Ulcerative Colitis Endoscopic Index of Severity [UCEIS]), and histological activity (Matts' histological grade) were compared between patients with and without BU.Results　Among 62 patients, 29.0% had BU. BU subscores showed stronger correlations with leucine-rich alpha-2 glycoprotein (LRG), MES, UCEIS, and Matts' histological grade than with the other symptomatic subscores. The Mayo and partial Mayo scores, MES, UCEIS, and Matts' histological grades were also significantly higher in the BU-present group, and all indices showed significant stepwise increases with higher BU subscores. Biochemical markers showed a similar pattern; patients with BU had higher LRG levels and white blood cell counts and lower hemoglobin and albumin levels than those with non-BU.Conclusion　BU is more strongly associated with the biochemical, endoscopic, and histological disease activity than other clinical symptoms in UC, suggesting that it may serve as a clinically meaningful indicator for disease assessment in UC.