Inflammatory bowel disease (IBD) – which includes Crohn’s disease (CD) and ulcerative colitis (UC) – is a chronic, progressive, relapsing, and heterogeneous condition driven by a complex interplay of genetic, microbial, immune, and environmental factors1, 2. With the rise of advanced therapies, the past two decades have seen increasing emphasis on defining treatment targets3, and more recently, on pursuing long-term disease-modifying goals4. However, the optimal approach to accurately evaluate these evolving targets is still a matter of debate within the scientific community.

Mucosal healing has represented the cornerstone of treatment targets in IBD for many years5. In patients with UC, many reports agree that a Mayo endoscopic subscore (MES) ≤ 1 is an optimal definition for mucosal healing6, although a deeper remission (defined as MES = 0) is associated with superior outcomes7. On the other hand, mucosal healing definition in CD is less stringent than UC and it is typically defined by the absence of ulcers, as the complete disappearance of all lesions is often unrealistic and might represent a misleading therapeutic target6. Although ileocolonoscopy remains the reference standard for disease assessment, its invasiveness, cost, procedural risks, and low patient acceptability limit its suitability for tight disease monitoring8.

In light of these considerations and giving the limitations of computed tomography enterography (CTE) due to ionizing radiations and magnetic resonance enterography (MRE) due to its high costs and limited accessibility9, interest has shifted toward intestinal ultrasound (IUS) as a non-invasive technique to assess cross-sectional healing in both CD and UC.

There is a clear need for standardized, non-invasive metrics of transmural activity. However, definitions of “transmural healing” and “ultrasound remission” remain heterogeneous across studies, hindering comparability and clinical uptake. A recent systematic review reported moderate to good accuracy for MRE, CTE, and IUS, highlighted IUS and MRE as the most scalable modalities, and underscored definitional heterogeneity as a key barrier10. We contend that standardization is the principal hurdle; once achieved, score-based IUS remission is able to carry prognostic value and may be a more attainable, clinically meaningful target than complete transmural healing, particularly in fibrotic phenotypes11.

In the following sections, we will explore the role of IUS in the cross-sectional evaluation of the bowel wall and discuss how we support the progressive shift towards the concept of “ultrasound remission”, a transition being supported by the development and validation of standardized IUS activity scores.