Editorial: Intestinal Ultrasound for the Assessment of Constipation—Out of the Shadows? Authors' Reply

We appreciate the insightful comments by Vos and colleagues on our expert position statement on the role of intestinal ultrasound (IUS) in luminal contents assessment [1]. IUS is a rapidly evolving area emerging as an alternative modality for the assessment of disorders of gut-brain interaction (DGBI) [2]. Patients with DGBI are exposed to more ionising radiation than healthy controls; IUS offers safety, cost effectiveness, and accuracy over conventional assessment methods [3]. Until recently, however, IUS for functional assessment has remained in the realm of paediatrics, with a paucity of adult studies and a lack of description or validation of sonographic parameters [4]. Our position statement [2] was intended to serve as initial guidance and a summation of current evidence. A narrative review has further summarised available evidence on luminal contents assessment [5]. A study performed in a DGBI cohort did not find a correlation between sonographic findings and symptoms, but did suggest that IUS was useful in identifying those patients who would benefit from therapy for constipation rather than treatment of diarrhoea due to identification of faecal loading [6]. Together, these set the scene for IUS in the assessment of luminal contents in clinical practice. However, they clearly illustrate knowledge gaps and the need for further research. Small studies have shown that IUS is as accurate as computed tomography [7, 8]. However, prospective, blinded, and centrally read studies are required to measure the accuracy and validity of IUS in measuring luminal contents, to improve reliability and uptake in both clinical trials and practice [9]. The Sonographic Examination and Assessment of Ulcerative Colitis Associated Constipation (SEE UCAC trial, ACTRN12622001207707) is the first prospective, blinded, and centrally read study to directly compare the accuracy of luminal contents assessment against CT scan with ultrasound. Interim results of 63 patients suggest close correlation between IUS and CT in assessing luminal contents as well as excellent inter-rater agreement between sonographic parameters [10]. The body of evidence supporting the use of IUS in clinical practice has remained in the assessment of inflammation, particularly in adults. It is now with great optimism that we see the increasing interest and growing potential of IUS in the assessment of DGBI and luminal contents emerging from the shadows into the spotlight. Ryan M. Mathias: conceptualization; writing – original draft. Thomas M. Goodsall: writing – review and editing. Claire E. Parker: writing – review and editing. Alice S. Day: writing – review and editing. Yoon K. An: writing – review and editing. Brandon Baraty: writing – review and editing. Chamara Basnayake: writing – review and editing. Jakob Begun: writing – review and editing. Ray K. Boyapati: writing – review and editing. Rebecca Burgell: writing – review and editing. Michael T. Dolinger: writing – review and editing. Giovanni Maconi: writing – review and editing. Kerri L. Novak: writing – review and editing. Shintaro Sagami: writing – review and editing. Rebecca L. Smith: writing – review and editing. Ashish R. Srinivasan: writing – review and editing. Stuart A. Taylor: writing – review and editing. Vipul Jairath: writing – review and editing. Christopher Ma: writing – review and editing. Robert V. Bryant: writing – review and editing; Supervision. The authors declare no conflicts of interest. This article is linked to Mathias et al. papers. To view these articles, visit https://doi.org/10.1111/apt.70250 and https://doi.org/10.1111/apt.70300. The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.