The Emerging Role of Ultrasonography in Ulcerative Colitis.

Background/Objectives: Intestinal ultrasound (IUS) is a non-invasive and reliable technique for the assessment and monitoring of ulcerative colitis (UC) in the era of tight disease control, although its accuracy is reduced for rectal evaluation. Its utility is further enhanced by transperineal ultrasonography (TPUS) and has also been demonstrated in patients with acute severe ulcerative colitis (ASUC) and in the postoperative assessment of ileal pouch function. Methods: We performed a narrative review on the emerging applications of IUS in UC with the findings obtained from research on the abovementioned topic on the PubMed database. Our search terms were "inflammatory bowel disease", "IBD", "ulcerative colitis", "intestinal ultrasound", "TPUS", "HH", "point of care ultrasound", and "bowel ultrasound". Results: IUS can assess UC disease activity and could be used in monitoring treatment response. Rectal assessment may represent a limitation of standard IUS, but the use of TPUS can overcome this issue, thus also allowing pouch evaluation after surgery. Another emerging application of IUS is in ASUC, a potential life-threatening condition where complete endoscopic assessment may not be feasible, so IUS could be a valid technique to assess disease extension and, in the first days, response to rescue therapy. Moreover, the use of hand-held sonography (HH), with portable ultrasonographic devices allowing point-of-care, bedside examination in various settings, is rising, showing accuracy comparable to standard techniques. Conclusions: IUS is emerging as a valuable tool in the management of patients with UC and could be an attractive option for point-of-care evaluation in the diagnosis, monitoring and prediction of long-term disease course, even after surgery or in the setting of ASUC. Complementary tools, such as TPUS and hand-held ultrasound, represent promising technologies, requiring prospective multicenter validation before routine clinical implementation.