Review Article: Extending the Frontiers of Intestinal Ultrasound Knowledge, Performance and Expansion.

BACKGROUND: Intestinal ultrasonography (IUS) is increasingly utilised for diagnosing and monitoring IBD. Despite its cost-effectiveness, patient tolerance and suitability for serial bedside assessments, broad adoption has been limited by knowledge gaps in evidence, training and standardisation. AIMS: To summarise key knowledge gaps in the assessment of luminal disease activity, postoperative recurrence, complications, pouch-related disorders and the use of IUS in paediatrics, contrast enhancement, elastography, as well as education, training and future applications involving artificial intelligence. METHODS: We conducted a systematic umbrella review, following PRISMA guidelines, to map the current landscape of high-quality evidence and identify gaps in IUS research relevant to IBD. We searched MEDLINE from inception to February 2025 for systematic reviews, meta-analyses and consensus statements. We extracted data from eligible studies on design, outcomes and identified research gaps. Gaps were categorised by insufficient information, bias, inconsistency or lack of relevant data. RESULTS: Sixty of 507 studies met inclusion criteria. Key gaps included lack of validated and standardised IUS activity indices for Crohn's disease and ulcerative colitis, limited evidence for IUS in post-operative recurrence, paediatric populations and perianal or pouch disease. Data on the use of contrast-enhanced ultrasound and elastography were sparse. Small sample sizes, heterogeneous designs and inadequate follow-up limited most studies. Training, competency assessment and integration of artificial intelligence remain underexplored. CONCLUSIONS: Sizable gaps persist in the evidence base for IUS in IBD. Addressing these gaps through robust, multicentre studies and consensus-driven frameworks is essential to optimise the clinical and research utility of IUS in IBD management.