Gastrointestinal Ultrasound in Functional Disorders of the Gastrointestinal Tract - EFSUMB Consensus Statement

The learning curve for using intestinal ultrasonography

BACKGROUND AND AIMS

Intestinal ultrasonography (IUS) is challenging to learn. This prospective study examined how the accuracy of IUS increases with operator experience ("learning curve") and if prior abdominal ultrasound experience facilitates the learning process.

METHODS

The study included two trainees with limited abdominal ultrasound experience (< 50 exams) and two with extensive experience (> 500 exams). Each trainee performed 99 examinations and reported four IUS findings. An expert sonographer repeated the exam, and concordance (k) between the expert and trainees was assessed in three consecutive testing periods of 33 exams each.

RESULTS

A progressive improvement in concordance was observed for all IUS findings from Period 1 to Period 3, overall and for both groups of trainees, although those with experience in abdominal ultrasound had faster learning curves. The minimum number of examinations required to achieve concordance with the expert operator for detecting increased bowel wall thickness was 84 and detecting bowel dilatation was 79. However, a minimum of 97 examinations was necessary to achieve concordance for detecting intra-abdominal complications, considered an advanced IUS competence.

CONCLUSION

Basic competence in IUS can be acquired with relatively few examinations, while advanced competence requires more extensive training, particularly for gastroenterologists without abdominal ultrasound experience.

Moving beyond Symptom Criteria to Diagnose and Treat Functional Disorders: Patient-Reported Symptoms of Functional Lower Gastrointestinal Disorders Correlate Poorly with Objective Assessment of Luminal Contents Seen on Intestinal Ultrasound

Background/Objectives: The diagnosis of lower functional gastrointestinal disorders (FGIDs) is currently based on subjective and unreliable patient-reported symptoms, with significant clinical overlap between diagnosed phenotypes. Objective biomarkers are urgently sought. Gastrointestinal ultrasound (GIUS) can objectively and non-invasively assess luminal contents. This study aimed to assess the utility of GIUS in phenotyping patients with lower FGIDs. Methods: Patients with lower FGIDs underwent a GIUS and completed the Rome IV Diagnostic Questionnaire, SAGIS questionnaire, and 100 mm VAS score for overall symptom severity. The faecal loading score (FLS) was obtained using a modified Leech score, where an FLS of >37 was consistent with clinically significant constipation. Results: Eighty-eight patients fulfilled the study requirements. In total, 56 met the Rome IV criteria for irritable bowel syndrome (IBS) subtypes, while 23 met the criteria for functional constipation (FC), 4 for functional diarrhoea (FD), and 5 for other diagnoses. Patients reporting constipation-predominant symptoms had a significantly higher median FLS than those describing diarrhoea-predominant symptoms (FLS = 40 [IQR 20.0-53.3] vs. 13.3 [IQR 6.7-40.0], respectively). However, 27% of patients describing diarrhoea had significant faecal loading on GIUS, and of those who described constipation, 34% did not have significant faecal loading. Sensitivity and specificity for the detection of FLS-indicated constipation by the Rome IV criteria were low at 59% and 66%, respectively. Conclusions: The symptom-based diagnosis of FGID subtypes based on the Rome IV criteria is a poor predictor of faecal loading. These findings should prompt further exploration of the limitations of symptom-based assessment and a shift towards physiological assessment of patients with FGIDs such as gastrointestinal ultrasound to develop more targeted therapy. Future research is underway to determine if targeting objective physiological endpoints results in improved clinical outcomes.

Recent advances in measuring the effects of diet on gastrointestinal physiology: Probing the "leaky gut" and application of real-time ultrasound

There is a large pool of ideas in both mainstream and non-mainstream medicine on how diet can be manipulated in order to treat or prevent illnesses. Despite this, our understanding of how specific changes in diet influence the structure and function of the gastrointestinal tract is limited. This review aims to describe two areas that might provide key information on the integrity and function of the gastrointestinal tract. First, demystifying the "leaky gut syndrome" requires rational application and interpretation of tests of intestinal barrier function. Multiple ways of measuring barrier function have been described, but the inherent difficulties in translation from animal studies to humans have created misinterpretations and misconceptions. The intrinsic nature of intestinal barrier function is dynamic. This is seldom considered in studies of intestinal barrier assessment. To adequately understand the effects of dietary interventions on intestinal barrier function, background barrier function in different regions of the gut and the dynamic responses to stressors (such as psychological stress) should be assessed as a minimum. Second, intestinal ultrasound, which is now established in the assessment and monitoring of inflammatory bowel disease, has hitherto been poorly evaluated in assessing real-time intestinal function and novel aspects of structure in patients with disorders of gut-brain interaction. In conclusion, a more complete functional and structural profile that these investigations enable should permit a greater understanding of the effects of dietary manipulation on the gastrointestinal tract and provide clinically relevant information that, amongst other advantages, might permit opportunities for personalized health care delivery.

Meta-analysis: Intestinal ultrasound to evaluate colonic contents and constipation

BACKGROUND

Constipation can be diagnosed clinically using the Rome criteria. Ultrasound (US), which lacks the radiation exposure of conventional X-ray, holds promise as a non-invasive tool to evaluate colonic contents and constipation.

AIM

To examine the role of US in the assessment of constipation.

METHODS

We performed a systematic search of Embase (OVID, 1984), Medline (Ovid, 1946), Cochrane Central, ClinicalTrials.gov and Australia New Zealand Clinical Trials Registry from database inception to 26 January 2024 according to PRISMA guidelines and prospectively registered with PROSPERO. All studies using US to assess constipation or colonic contents in either adults or children were included. Rectal diameter measurements were pooled in meta-analysis. Risk of bias was assessed using the Newcastle Ottawa Scales and Joanna Briggs Institute checklists.

RESULTS

Of 12,232 studies screened, 51 articles (6084 patients; 3422 children) describing US to assess symptoms in patients with constipation were included. Most studies used Rome criteria to diagnose constipation. Rectal diameter was associated with clinical constipation in 29 paediatric studies (3331 patients). Meta-analysis showed the mean rectal diameter of constipated patients was significantly higher than controls (mean difference 12 mm, 95% confidence intervals (CI): 6.48, 17.93, p < 0.0001, n = 16 studies). Other features of constipation on US included posterior acoustic shadowing and echogenicity of luminal contents.

CONCLUSION

US is an appealing imaging modality to assess luminal contents and constipation. Further well-designed studies are required to validate US metrics that accurately identify constipation.

Basic practices for gastrointestinal ultrasound

The standard diagnostic modalities for gastrointestinal (GI) diseases have long been endoscopy and barium enema. Recently, trans-sectional imaging modalities, such as computed tomography and magnetic resonance imaging, have become increasingly utilized in daily practice. In transabdominal ultrasonography (US), the bowel sometimes interferes with the observation of abdominal organs. Additionally, the thin intestinal walls and internal gas can make structures difficult to identify. However, under optimal US equipment settings, with identification of the sonoanatomy and knowledge of the US findings of GI diseases, US can be used effectively to diagnose GI disorders. Thus, the efficacy of GIUS has been gradually recognized, and GIUS guidelines have been published by the World Federation for Ultrasound in Medicine and Biology and the European Federation of Societies for Ultrasound in Medicine and Biology. Following a systematic scanning method according to the sonoanatomy and precisely estimating the layered wall structures by employing color Doppler make diagnosing disease and evaluating the degree of inflammation possible. This review describes current GIUS practices from an equipment perspective, a procedure for systematic scanning, typical findings of the normal GI tract, and 10 diagnostic items in an attempt to help medical practitioners effectively perform GIUS and promote the use of GIUS globally.

Point-of-care Ultrasound of the Gastrointestinal Tract

The widespread use of portable ultrasound scanners has promoted the concept of point of care ultrasound (POCUS), namely "ultrasound performed bedside and interpreted directly by the clinician." The purpose of this short review is to outline how POCUS can be used in patients with diseases of the gastrointestinal (GI) tract. POCUS is not a replacement for comprehensive ultrasound, but rather allows physicians immediate access to clinical imaging for rapid diagnosis and efficient work-up and treatment of the patients. There are many indications for doing POCUS of the GI tract, including abdominal pain, diarrhea, palpable masses, and to detect fluid or free air in the abdominal cavity. To improve the visibility of deeper parts of the abdomen, the graded compression technique with the scan head is useful. During POCUS, the operator should look for signs of severe pathology including target lesions, the pseudo-kidney sign, the onion sign, dilated bowel loops, gastric retention, free fluid, and free air, depending on the actual clinical problem. We conclude that POCUS of the GI tract is very useful to provide a rapid diagnosis in many clinical scenarios.

Functional Abdominal Cramping Pain: Expert Practical Guidance

Functional abdominal cramping pain (FACP) is a common complaint, which may present either on its own or in association with a functional gastrointestinal disorder. It is likely caused by a variety of, probably partly unknown, etiologies. Effective management of FACP can be challenging owing to the lack of usable diagnostic tools and the availability of a diverse range of treatment approaches. Practical guidance for their selection and use is limited. The objective of this article is to present a working definition of FACP based on expert consensus, and to propose practical strategies for the diagnosis and management of this condition for physicians, pharmacists, and patients. A panel of experts on functional gastrointestinal disorders was convened to participate in workshop activities aimed at defining FACP and agreeing upon a recommended sequence of diagnostic criteria and management recommendations. The key principles forming the foundation of the definition of FACP and suggested management algorithms include the primacy of cramping pain as the distinguishing symptom; the importance of recognizing and acting upon alarm signals of potential structural disease; the recognition of known causes that might be addressed through lifestyle adjustment; and the central role of antispasmodics in the treatment of FACP. The proposed algorithm is intended to assist physicians in reaching a meaningful diagnostic endpoint based on patient-reported symptoms of FACP. We also discuss how this algorithm may be adapted for use by pharmacists and patients.

Practical Recommendation of the Scientific Сommunity for Human Microbiome Research (CHMR) and the Russian Gastroenterological Association (RGA) on Small Intestinal Bacterial Overgrowth in Adults

Aim. To optimize the choice of treatment strategies by physicians and gastroenterologists to improve treatment and prevention of small intestinal bacterial overgrowth (SIBO) in adults.

Key points. SIBO is a condition characterized by an increased amount and/or abnormal composition of the microbiota in the small intestine. Clinically, the syndrome is manifested by nonspecific gastroenterological complaints and the development of malabsorption syndrome. Most often, SIBO is associated with various chronic non- infectious diseases (both diseases of the gastrointestinal tract, and the cardiovascular system and the neuromuscular apparatus) and can affect the severity of their symptoms. Specific methods for diagnosing SIBO are the culture method and breath tests. The main approaches to the treatment of SIBO include the elimination of the underlying cause of its occurrence, the use of antibacterial drugs and adherence to dietary recommendations (elemental diet).

Conclusion. Small intestinal bacterial overgrowth is common in patients with various diseases, but has non-specific manifestations, so proper diagnosis of this condition is required. SIBO therapy involves prescription of antibacterial agents, the most studied of which is the non-absorbable antibiotic rifaximin-α.