A comprehensive guide to intestinal ultrasound in ulcerative colitis

Ulcerative colitis (UC) is traditionally considered a mucosal disease, with endoscopy as the gold standard for diagnosis and monitoring. However, emerging evidence increasingly supports the integration of intestinal ultrasound (IUS) as a non-invasive, accurate, and dynamic imaging modality in the management of UC. Traditionally confined to the assessment of Crohn's disease due to its transmural nature, IUS has demonstrated strong associations with clinical, endoscopic, and histologic scores in UC, enabling real-time assessment of disease activity, therapeutic response, and long-term outcomes. In this comprehensive review, we summarize the current evidence on the diagnostic and prognostic utility of IUS in UC, with a focus on validated ultrasonographic scores. Moreover, we explore novel applications of IUS in special clinical settings, including acute severe ulcerative colitis (ASUC), as well as in specific disease localizations such as proctitis and pouchitis, where transperineal ultrasound (TPUS) may offer diagnostic advantages. Furthermore, we review its emerging role in point-of-care scenarios and its utility within specific patient populations, notably pediatric patients.