Ultrasound assessment of gastrointestinal luminal contents: a narrative review

Gastro-intestinal ultrasound (GIUS) is a non-invasive and cost-effective tool, widely used as a first-line diagnostic method in patients presenting with abdominal complaints, especially in patients affected by inflammatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis. In this setting, gastro-intestinal ultrasound has been especially used to evaluate the bowel wall features (thickening, stratification, vascularization) and complications related to IBD (fistulas, abscesses). Nevertheless, gastro-intestinal ultrasound can be also used to detect and evaluate the content of several segments of the gut. In fact, there is a growing interest in utilizing GIUS for suspected functional disorders, where assessing intestinal content may play a significant diagnostic role, as well as directing therapy. In our review, we provided a sonographic description of GIUS appearances of bowel content in various pathological and physiological conditions, offering potential applications in clinical practice and providing insights for further research.