Crohn's disease (CD) is a nonspecific chronic inflammatory condition characterized by a protracted course with alternating periods of relapse and remission. Even patients who achieve deep remission remain prone to recurrence and require long-term follow-up. While various monitoring methods are available, endoscopy plays a primary role in the management and diagnosis of CD; however, its relative invasiveness and the need for bowel preparation limit the feasibility of continuous monitoring. In contrast, transabdominal intestinal ultrasound offers advantages such as non-invasiveness, absence of radiation, good patient tolerance, and low cost, making it suitable for long-term monitoring. However, most studies have focused on exploring its concordance with disease activity and endoscopic findings, with only a limited number of studies examining its clinical significance for long-term prognosis.
Therefore, we conducted a multicenter prospective study involving 18 months of follow-up in CD patients who achieved deep remission. Based on the follow-up results, patients were divided into relapse and non-relapse groups. Stratified analysis was performed according to the Montreal classification to compare color Doppler ultrasound parameters between the two groups and within each stratum, and to establish a predictive model.