From the Journals

Bowel ultrasound may overtake colonoscopy in Crohn’s

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A 'significant financial burden' avoided

Patients with Crohn’s disease (CD) undergo multiple colonoscopies during their lifetime. Endoscopic assessment is often necessary to determine extent and severity of inflammation to guide choice of therapy, assess mucosal healing on current therapy, and for surveillance examination for colorectal dysplasia. Multiple colonoscopies over a lifetime present a significant financial burden for patients. The invasive nature of the procedure, along with the small but potential risk of perforation and patient discomfort make for an undesirable experience. Cross-sectional imaging offers the advantage of noninvasive modality to assess bowel wall and extraluminal complications related to CD. Bowel ultrasound, performed as point of care imaging by gastroenterologists, is an emerging imaging alternative to visualize the bowel.

In the study by Allocca et al., the authors developed a bowel ultrasound–based score incorporating bowel wall thickness, pattern, flow, and presence of extraluminal complications. The score was developed by comparing ultrasound parameters with colonoscopy findings for each segment of the colon and terminal ileum. In a cohort of 225 patients, a bowel ultrasound score of >3.52 along with at least one extraluminal complication, baseline fecal calprotectin of >250 mcg/g, and male gender were linked with adverse outcomes within 12 months (defined as need for steroids, change of therapy, hospitalization, or surgery).

Dr. Manreet Kaur

While these observations need to be validated externally, this study further consolidates the role for bowel ultrasound as a viable imaging modality to monitor disease and response to therapy in CD. Prior studies have shown bowel ultrasound is a valid alternative to MR enterography – without the expense, limited availability, and need for gadolinium contrast. As the therapeutic targets in IBD move toward mucosa healing, bowel ultrasound offers the promise of a cost-effective, noninvasive, point-of care test that can be performed during an office consultation. The operator dependent nature of this modality may limit its uptake and utilization. The International Bowel Ultrasound Group (IBUS) has collaborated with the European Crohn’s and Colitis organization as well as the Canadian Association of Gastroenterology to establish training and research in bowel ultrasound. Soon, patients can expect a bowel ultrasound to become part of their routine assessment during an office consultation.

Manreet Kaur, MD, is medical director of the Inflammatory Bowel Disease Center and an associate professor in the division of gastroenterology and hepatology at Baylor College of Medicine, Houston. She has no relevant conflicts of interest.



Bowel ultrasound predicts the clinical course of Crohn’s disease for up to 1 year, according to results of a prospective trial involving 225 patients.

After additional confirmation in larger studies, ultrasound could serve as a noninvasive alternative to colonoscopy for monitoring and predicting disease course, reported lead author Mariangela Allocca, MD, PhD, of Humanitas University, Milan, and colleagues.

“Frequent colonoscopies are expensive, invasive, and not well tolerated by patients, thus noninvasive tools for assessment and monitoring are strongly needed,” the investigators wrote in Clinical Gastroenterology and Hepatology. “Bowel ultrasound accurately detects inflammatory bowel disease activity, extent, and complications, particularly in Crohn’s disease. Considering its low cost, minimal invasiveness ... and easy repeatability, bowel ultrasound may be a simple, readily available tool for assessing and monitoring Crohn’s disease.”

To test this hypothesis, Dr. Allocca and colleagues enrolled 225 consecutive patients with ileal and/or colonic Crohn’s disease diagnosed for at least 6 months and managed at a tertiary hospital in Italy. All patients underwent both colonoscopy and bowel ultrasound with no more than 3 months between each procedure.

Colonoscopy results were characterized by the Simplified Endoscopic Score for Crohn’s disease (SES-CD), whereas ultrasound was scored using a several parameters, including bowel wall pattern, bowel thickness, bowel wall flow, presence of complications (abscess, fistula, stricture), and characteristics of mesenteric lymph nodes and tissue. Ultrasound scores were considered high if they exceeded a cut-off of 3.52, which was determined by a receiver operating characteristic curve analysis.

Participants were followed for 12 months after baseline ultrasound. The primary objective was to determine the relationship between baseline ultrasound findings and negative disease course, defined by steroid usage, need for surgery, need for hospitalization, and/or change in therapy. The secondary objective was to understand the relationship between ultrasound findings and endoscopy activity.

Multivariable analysis revealed that ultrasound scores greater than 3.52 predicted a negative clinical disease course for up to one year (odds ratio, 6.97; 95% confidence interval, 2.87-16.93; P < .001), as did the presence of at least one disease complication at baseline (OR, 3.90; 95% CI, 1.21-12.53; P = 0.21). A worse clinical course at one-year was also predicted by a baseline fecal calprotectin value of at least 250 mcg/g (OR, 5.43; 95% CI, 2.25-13.11; P < .001) and male sex (OR, 2.60; 95% CI, 1.12-6.02; P = .025).

Investigators then assessed individual disease outcomes at 12 months and baseline results. For example, high ultrasound score and calprotectin at baseline each predicted the need for treatment escalation. In comparison, disease behavior (inflammatory, stricturing, penetrating) and C reactive protein predicted need for corticosteroids. The only significant predictor of hospitalization a year later was CRP.

“[B]owel ultrasound is able to predict disease course in Crohn’s disease patients,” they wrote. “It may identify patients at high risk of a negative course to adopt effective strategies to prevent any disease progression. Our data need to be confirmed and validated in further large studies.”

The investigators disclosed relationships with Janssen, AbbVie, Mundipharma, and others.

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