An international panel has published the first consensus recommendations for using intestinal ultrasound to detect Crohn’s disease recurrence after bowel resection, offering gastroenterologists a standardised, non-invasive alternative to surveillance colonoscopy.
The guidance, published in Lancet Gastroenterology and Hepatology [link here] emerged from a modified RAND/UCLA appropriateness method study involving 16 experts from nine countries, including gastroenterologists, colorectal surgeons and radiologists. The panel rated 122 statements across two voting rounds before an in-person ratification meeting in Berlin in February 2025.
The impetus is clear. Postoperative endoscopic recurrence occurs in 70 to 90 per cent of patients within one year without prophylactic treatment, yet adherence to surveillance colonoscopy remains low. Colonoscopy is costly, invasive, requires bowel preparation, and is generally less accepted by patients with Crohn’s disease than imaging alternatives.
The systematic review underpinning the consensus found intestinal ultrasound had a pooled sensitivity of 0.89 and specificity of 0.76 for detecting recurrence. Using optimal sonographic definitions, sensitivity could rise to 0.93 and specificity to 0.85.
The panel agreed that intestinal ultrasound findings in the neoterminal ileum and its inlet are “most likely to reflect clinically meaningful disease activity” and should anchor postoperative assessment. Scanning should not be performed within four weeks of surgery, to avoid confounding findings with postoperative oedema or complications, and the first formal assessment should occur between three and 12 months post-surgery.
Recommended sonographic parameters include bowel wall thickness, stratification and vascularity; mesenteric inflammatory fat and lymphadenopathy; luminal narrowing; and complications including abscess, fistula, sinus tract, stricture, and prestenotic dilation. A bowel wall thickness greater than 3.0 mm in the neoterminal ileum was endorsed as the threshold for recurrence, though the panel noted a higher cutoff may be more appropriate at the anastomosis itself, where surgical stapling can cause wall thickening that exceeds 3 mm in the absence of active disease.
The panel also stressed that postoperative anatomy can confound ultrasound interpretation, and recommended that sonographers review operative reports and have specific experience assessing post-surgical bowel. Previous research cited by the panel suggests 50 to 200 scans are required to develop technical proficiency.
One area that resisted consensus was submucosal layer thickness. Despite being voted appropriate in the second survey round, it was excluded from final recommendations after extensive debate at the ratification meeting about measurement inconsistencies and the absence of prognostic data. The panel described it as “an area of research priority.”
The authors acknowledged that consensus was not achievable in all areas due to insufficient empirical data, no single unifying definition of active disease was established, and the panel was weighted toward gastroenterologists rather than surgeons or radiologists.
They called for development of “a reliable, validated index for Crohn’s disease postoperative recurrence” as the critical next step, and for prospective trials to determine whether early intervention guided by intestinal ultrasound changes disease outcomes.
The study was funded by Johnson and Johnson Innovative Medicine.