Andrews, Christopher N

ABSTRACT Background The assessment of gastrointestinal (GI) motility disorders is limited by the invasive, resource‐intensive, and subjective nature of current testing. Artificial Intelligence (AI) is being applied to address these challenges. This review aimed to comprehensively identify, appraise, and synthesize the spectrum of AI applications in GI motility diagnostics. Methods A systematic search of PubMed, Embase, Scopus, Web of Science, and Medline for original studies was conducted in March 2025. Results were narratively synthesized and grouped by anatomic region. Key Results Of 1383 articles, 90 primary studies met the inclusion criteria. In the esophagus ( n = 31), the primary focus was automation of High‐Resolution Esophageal Manometry (HREM), pH impedance, and Functional Luminal Imaging Probe (FLIP) panometry analysis. In the gastroduodenum ( n = 21), studies looked to improve diagnostic accuracy and interpretability of legacy electrogastrography (EGG). In the small and large intestine ( n = 19), AI was used to determine transit time and predict post‐operative ileus. In the anorectum ( n = 9), tools focused on standardizing manometry interpretation. Review of pan‐GI applications ( n = 10) highlighted AI's application to wireless capsule endoscopy and bowel sounds analysis. While promising, all areas need more rigorous research and external validation before widespread deployment. Conclusions and Inferences AI will play an essential role in improving and automating the interpretation of GI motility diagnostics. However, even the most promising models require large‐scale prospective validation before clinical implementation. Trial Registration PROSPERO (ID: 1128662)

INTRODUCTION: Chronic neurogastroduodenal disorders are heterogeneous and thought to lie on a spectrum of disease encompassing both sensory and neuromuscular pathologies. Abnormalities of interstitial cells of Cajal (ICC), a subset of which generate pacemaker signals and subsequently motility, have been implicated in their pathophysiology. We systematically reviewed the literature to pool ICC deficits observed in chronic neurogastroduodenal disorders. METHODS: Studies quantifying gastric ICC from the corpus or antrum, in adult patients with gastroparesis, functional dyspepsia (FD), or chronic nausea and vomiting syndromes (CNVS) were analyzed (PROSPERO: CRD42024613226). MEDLINE, Embase and CENTRAL databases were searched systematically. Random effects meta-analyses were used to compare ICC counts by disorder group with subgroup analysis by quantification methodology. RESULTS: Overall, 2,158 studies were screened and 22 included. Comparative studies (n = 12) showed patients with chronic neurogastroduodenal disorders (n = 167 with gastroparesis, n = 19 with FD ± CNVS) had lower ICC counts than nondiabetic controls (n = 130); standardized mean difference −1.58, 95% confidence interval −2.09 to −1.07, P < 0.0001, with more severe deficits in gastroparesis compared to FD ± CNVS (standardized mean difference [SMD] −0.44, P = 0.048). A spectrum of ICC deficits was evident in a subgroup of studies using gold-standard methods with c-KIT antibody and 4',6-diamidino-2-phenylindole-stained nuclei confirmation (7 studies, 246 patients: mean ICC counts 2.29 in gastroparesis vs 3.49 in FD ± CNVS, and 5.27 in controls; P < 0.001 all comparisons). Most studies were at high risk of bias (n = 21). DISCUSSION: Marked depletion of ICC is a consistent finding in neurogastroduodenal disorders. A spectrum of disease is revealed, with greater depletion associated with delayed emptying. Techniques for clinically defining ICC-driven gastric neuromuscular dysfunction should be prioritized.

INTRODUCTION: Gastroparesis is a debilitating gastroduodenal disorder for which gastric peroral endoscopic myotomy (GPOEM) has emerged as an efficacious treatment option. However, response to GPOEM varies between 50% and 80%, such that preoperative predictors of treatment success are needed to guide patient selection. METHODS: We performed a systematic review to identify predictors of clinical and functional response to GPOEM among adult patients with gastroparesis (PROSPERO: CRD42023457359). MEDLINE, Embase, and CENTRAL databases were searched systematically for studies reporting outcomes after GPOEM in September 2023. A narrative synthesis of predictive factors on univariable and multivariable analysis was performed with consideration of response rates through meta-analysis and evaluation of discrimination if prognostic models were developed. Risk Of Bias In Non-randomized Studies - of Exposures (ROBINS-E) was used for risk of bias assessment. RESULTS: Of 1899 articles reviewed, 30 were included. The GPOEM response rate was 63.1% (95% confidence interval 56.3%–69.5%) with most studies defining clinical success on the basis of improvement in gastroparesis cardinal symptom index (87%, 26/30). Older age, shorter duration of gastroparesis, nondiabetic etiology, lower body mass index, and response to intrapyloric botulinum toxin were associated with positive response to GPOEM on multivariable analyses. Predictors on physiological tests such as EndoFLIP or gastric emptying scintigraphy were inconsistent. No prognostic models underwent external validation. DISCUSSION: Currently, there are limited reproducible predictors of response to GPOEM among patients with refractory gastroparesis. Robust prospective studies investigating scalable, reproducible, and actionable biomarkers of treatment response are required.

Chronic nausea and vomiting syndromes (NVSs) are prevalent and debilitating disorders. Putative mechanisms include gastric neuromuscular disease and dysregulation of brain-gut interaction, but clinical tests for objectively defining gastric motor function are lacking. A medical device enabling noninvasive body surface gastric mapping (BSGM) was developed and applied to evaluate NVS pathophysiology. BSGM was performed in 43 patients with NVS and 43 matched controls using Gastric Alimetry (Alimetry), a conformable high-resolution array (8 × 8 electrodes; 20-mm interelectrode spacing), wearable reader, and validated symptom-logging app. Continuous measurement encompassed a fasting baseline (30 minutes), 482-kilocalorie meal, and 4-hour postprandial recording, followed by spectral and spatial biomarker analyses. Meal responses were impaired in NVS, with reduced amplitudes compared to controls (median, 23.3 microvolts versus 38.0 microvolts, P < 0.001), impaired fed-fasting power ratios (1.1 versus 1.6, P = 0.02), and disorganized slow waves (spatial frequency stability, 13.6 versus 49.5; P < 0.001). Two distinct NVS subgroups were evident with indistinguishable symptoms (all P > 0.05). Most patients (62%) had normal BSGM studies with increased psychological comorbidities (43.5% versus 7.7%; P = 0.03) and anxiety scores (median, 16.5 versus 13.0; P = 0.035). A smaller subgroup (31%) had markedly abnormal BSGM, with biomarkers correlating with symptoms (nausea, pain, excessive fullness, early satiety, and bloating; all r > 0.35, P < 0.05). Patients with NVS share overlapping symptoms but comprise distinct underlying phenotypes as revealed by a BSGM device. These phenotypes correlate with symptoms, which should inform clinical management and therapeutic trial design.

Summary Background Medications can affect gastrointestinal tract motility. However, their effects on oesophageal motility in particular are often not as widely known or may be underestimated. Aim To review the effect of existing medication use on high‐resolution oesophageal manometry (HRM) in a ‘real‐world’ setting. Methods Adult patients with upper gut symptoms and normal endoscopy or imaging who had HRM over a 22‐month period were analysed. Achalasia and major disorders of peristalsis were excluded. All medications taken within 24 hours of the procedure were prospectively recorded and compared with HRM results, controlling for age, gender and proton pump inhibitor use. Results A total of 502 patients (323 female, mean age 51) were recruited. Of these, 41.2% had normal oesophageal HRM, while 41.4% had ineffective oesophageal motility (IOM) and 7.6% had oesophagogastric junction outflow obstruction (OGJOO). Serotonin/norepinephrine reuptake inhibitors (SNRI) and opioids were associated with significantly higher resting lower oesophageal sphincter pressure. Benzodiazepines and opioids were associated with elevated integrated relaxation pressure. SNRI and inhaled beta‐agonists were associated with increased distal contractile index, whereas calcium channel blockers were associated with a lower distal contractile index. Odds ratio of being on anticholinergics was higher in IOM patients vs normal (3.6, CI 1.2‐10.8). Odds ratio for anticholinergics, inhaled beta‐agonists, anticonvulsants, SNRIs and opioids (trend) were all > 3 for OGJOO patients vs normal. Conclusion Many medication classes are associated with abnormal HRM variables and diagnoses such as OGJOO and IOM; some of these associations are probably causal. These possible links should be taken into consideration during manometry interpretation.

Objective Antireflux surgery can be proposed in patients with GORD, especially when proton pump inhibitor (PPI) use leads to incomplete symptom improvement. However, to date, international consensus guidelines on the clinical criteria and additional technical examinations used in patient selection for antireflux surgery are lacking. We aimed at generating key recommendations in the selection of patients for antireflux surgery. Design We included 35 international experts (gastroenterologists, surgeons and physiologists) in a Delphi process and developed 37 statements that were revised by the Consensus Group, to start the Delphi process. Three voting rounds followed where each statement was presented with the evidence summary. The panel indicated the degree of agreement for the statement. When 80% of the Consensus Group agreed (A+/A) with a statement, this was defined as consensus. All votes were mutually anonymous. Results Patients with heartburn with a satisfactory response to PPIs, patients with a hiatal hernia (HH), patients with oesophagitis Los Angeles (LA) grade B or higher and patients with Barrett’s oesophagus are good candidates for antireflux surgery. An endoscopy prior to antireflux surgery is mandatory and a barium swallow should be performed in patients with suspicion of a HH or short oesophagus. Oesophageal manometry is mandatory to rule out major motility disorders. Finally, oesophageal pH (±impedance) monitoring of PPI is mandatory to select patients for antireflux surgery, if endoscopy is negative for unequivocal reflux oesophagitis. Conclusion With the ICARUS guidelines, we generated key recommendations for selection of patients for antireflux surgery.

OBJECTIVES: Prokinetics are recommended for the treatment of functional dyspepsia (FD) but systematic reviews give conflicting results on the efficacy of these agents. We have therefore conducted an updated systematic review to support the 2017 joint ACG/CAG dyspepsia guidelines. METHODS: Electronic databases, including MEDLINE, EMBASE, and CENTRAL, were searched until September 2017 for randomized controlled trials (RCTs) comparing either prokinetics and placebo or two types of prokinetics to improve FD symptoms. The primary outcome was absence or improvement of dyspeptic symptoms at the end of treatment. Double-blind eligibility assessment and data extraction was performed. Pooled risk ratios of symptoms persisting or adverse events occurring, and standardized mean difference of quality-of-life (QoL) scores with 95% CI, using a random effects model, were calculated. Quality of evidence was assessed using GRADE. RESULTS: The search identified 1388 citations; 38 studies in 35 papers were included. Of these, 29 trials comparing prokinetics with placebo were found. There was a statistically significant effect of prokinetic treatment in reducing global symptoms of FD (RR 0.81, 95% CI 0.74 to 0.89; I 2 91%; NNT 7), regardless of FD subtype or ethnicity. When comparing two types of prokinetic, the most commonly used comparator was domperidone. There was no difference in reducing global symptoms (RR 0.94, 95% CI 0.83 to 1.07). QoL was not improved with prokinetic treatment. The adverse events with individual prokinetics were not different from placebo, except for cisapride. The GRADE assessment rated the quality of the evidence in each outcome as very low. CONCLUSIONS: From the current evidence, prokinetics may be effective for the treatment in all subtypes of FD, with very low quality of evidence. There was no difference between prokinetics for dyspeptic symptom improvement. High-quality RCTs with large sample sizes of FD patients are needed to verify the efficacy of prokinetics.

Not so long ago, physicians construed the irritable bowel syndrome (IBS) as being a neurotic trait: it was all in the head. Today most clinicians believe that the main abnormality lies in the brain (and spinal cord), which reacts abnormally to stimuli from the gut. Recent studies are identifying a basis for these neural changes - low grade inflammation in the gut - which may play a key role in IBS.

BACKGROUND: It is not clear if starting intravenous proton pump inhibitors (IV PPI) before endoscopic therapy provides additional benefit over starting it afterward in patients with high-risk ulcer stigmata of peptic ulcer disease.METHODS: All patients who received IV pantoprazole bolus and infusion and underwent endoscopy in six Canadian hospitals over 20 months were reviewed. Only patients with high-risk ulcer stigmata (arterial bleeding, oozing, nonbleeding visible vessel or adherent clot) were included. Patients receiving IV PPI before endoscopy (before group) were compared with those who received it after endoscopy (after group) with respect to endoscopic findings and, secondarily, to patient demographics and clinical outcomes.RESULTS: The demographics and baseline characteristics of the before group (n=57) and the after group (n=109) were similar. The before group was more likely to have had IV PPI started outside of daytime hours, and median time to endoscopy in patients admitted with upper gastrointestinal bleeding was 24 h (interquartile range 9.5 to 35) in the before group and 11.3 h (interquartile range 3.7 to 17.2) in the after group ( P<0.0001). At the time of endoscopy, 33% of patients in the before group had actively bleeding lesions (Forrest 1a or 1b) compared with 54% in the after group (P=0.01), but there were no significant differences in rebleeding, surgical rates, intensive care unit admission or death between the groups.CONCLUSION: IV PPI infusions before endoscopy may lower the proportion of actively bleeding peptic ulcer lesions at endoscopy, but this finding does not appear to affect rates of rebleeding, surgery or death.