Managing Ulcerative Colitis and Crohn's Disease: Should the Target Be Endoscopy, Histology, or Both?

In inflammatory bowel disease (IBD), mucosal healing is the primary long-term treatment goal, encompassing both endoscopic and histological outcomes. This paper aims to overview the ability of new treatment options to promote endoscopic and histological healing and to discuss the prognostic significance of endoscopic and histological outcomes. The analysis included randomized-controlled trials (published since 2020) focused on the impact of pharmacological interventions on endoscopic and histological remission in IBD. Even though the Mayo endoscopic subscore is routinely used, the application of validated scoring systems for ulcerative colitis is uncommon. In Crohn's disease (CD), the application of endoscopic scores remains limited to clinical studies. The standardized evaluation of histological features has been performed in several recent ulcerative colitis trials, resorting mostly to the Geboes score and the Nancy histological index. Still, the use of histological scores for CD remains elusive. Current evidence underscores that histological remission conveys the best long-term prognosis, supporting the inclusion of histology as a treatment guide in ulcerative colitis. In CD, data are promising but originated from a few retrospective studies. Further efforts are warranted to: (1) use validated histological indexes for ulcerative colitis, aiming their adoption as treatment targets; (2) promote the validation and utilization of histological scores for CD, at least in clinical studies; (3) confirm the prognostic impact of histological remission in CD; (4) integrate artificial intelligence assets to support grading, particularly in the setting of histology; (5) prospectively define the monitoring frequency of IBD patients who achieved histological remission. This paper reviews the ability of new therapies to induce endoscopic and histological healing in inflammatory bowel disease. Also, it discusses the impact of such outcomes on prognosis. In ulcerative colitis (UC), endoscopic scores are commonly used. However, the use of endoscopic scores for Crohn's disease (CD) is limited. Studies show that histological remission is associated with the best long-term prognosis. This suggests that histology should be a treatment target for UC. For CD, there is less data available, but it shows promise. The evaluation of histological parameters is less standardized, particularly for CD. Validated endoscopic and histologic indexes should be used. Future research may establish the role of histological remission in predicting prognosis, particularly for CD.