Braden Kuo

Comparison of gastric emptying of a nondigestible capsule to a radio-labelled meal in healthy and gastroparetic subjects

Background  Gastric emptying scintigraphy (GES) using a radio‐labelled meal is used to measure gastric emptying. A nondigestible capsule, SmartPill, records luminal pH, temperature, and pressure during gastrointestinal transit providing a measure of gastric emptying time (GET).

Do Stool Form and Frequency Correlate With Whole-Gut and Colonic Transit? Results From a Multicenter Study in Constipated Individuals and Healthy Controls

OBJECTIVES:Despite a lack of supportive data, stool form and stool frequency are often used as clinical surrogates for gut transit in constipated patients. The aim of this study was to assess the correlation between stool characteristics (form and frequency) and gut transit in constipated and healthy adults.METHODS:A post hoc analysis was performed on 110 subjects (46 chronic constipation) from nine US sites recording stool form (Bristol Stool Scale) and frequency during simultaneous assessment of whole-gut and colonic transit by wireless motility capsule (WMC) and radio-opaque marker (ROM) tests. Stool form and frequency were correlated with transit times using Spearmans rank correlation. Accuracy of stool form in predicting delayed transit was assessed by receiver operating characteristic analysis.RESULTS:In the constipated adults (42 females, 4 males), moderate correlations were found between stool form and whole-gut transit measured by WMC (r=−0.61, P<0.0001) or ROM (−0.45, P=0.0016), as well as colonic transit measured by WMC (−0.62, P<0.0001). A Bristol stool form value <3 predicted delayed whole-gut transit with a sensitivity of 85% and specificity of 82% and delayed colonic transit with a sensitivity of 82% and specificity of 83%. No correlation between stool form and measured transit was found in healthy adults, regardless of gender. No correlation was found between stool frequency and measured transit in constipated or healthy adults. The correlation between stool frequency and measured transit remained poor in constipated adults with <3 bowel movements per week.CONCLUSIONS:Stool form predicts delayed vs. normal transit in adults. However, only a moderate correlation exists between stool form and measured whole-gut or colonic transit time in constipated adults. In contrast, stool frequency is a poor surrogate for transit, even in those with reduced stool frequency.

Gastroparesis and Functional Dyspepsia: Excerpts from the AGA/ ANMS Meeting

Background  Despite the relatively high prevelance of gastroparesis and functional dyspepsia, the aetiology and pathophysiology of these disorders remain incompletely understood. Similarly, the diagnostic and treatment options for these two disorders are relatively limited despite recent advances in our understanding of both disorders.

The Brain Circuitry Underlying the Temporal Evolution of Nausea in Humans

Nausea is a universal human experience. It evolves slowly over time, and brain mechanisms underlying this evolution are not well understood. Our functional magnetic resonance imaging (fMRI) approach evaluated brain activity contributing to and arising from increasing motion sickness. Subjects rated transitions to increasing nausea, produced by visually induced vection within the fMRI environment. We evaluated parametrically increasing brain activity 1) precipitating increasing nausea and 2) following transition to stronger nausea. All subjects demonstrated visual stimulus-associated activation (P < 0.01) in primary and extrastriate visual cortices. In subjects experiencing motion sickness, increasing phasic activity preceding nausea was found in amygdala, putamen, and dorsal pons/locus ceruleus. Increasing sustained response following increased nausea was found in a broader network including insular, anterior cingulate, orbitofrontal, somatosensory and prefrontal cortices. Moreover, sustained anterior insula activation to strong nausea was correlated with midcingulate activation (r = 0.87), suggesting a closer linkage between these specific regions within the brain circuitry subserving nausea perception. Thus, while phasic activation in fear conditioning and noradrenergic brainstem regions precipitates transition to strong nausea, sustained activation following this transition occurs in a broader interoceptive, limbic, somatosensory, and cognitive network, reflecting the multiple dimensions of this aversive commonly occurring symptom.

Wireless pH‐motility capsule for colonic transit: prospective comparison with radiopaque markers in chronic constipation

Background  Colon transit (CT) measurements are used in the management of significant constipation. The radiopaque marker (ROM) method provides limited information.

The assessment of regional gut transit times in healthy controls and patients with gastroparesis using wireless motility technology

Background  Wireless pH and pressure motility capsule (wireless motility capsule) technology provides a method to assess regional gastrointestinal transit times.

Motility of the antroduodenum in healthy and gastroparetics characterized by wireless motility capsule.

Background  The wireless motility capsule (WMC) measures intraluminal pH and pressure, and records transit time and contractile activity throughout the gastrointestinal tract. Our hypothesis is that WMC can differentiate antroduodenal pressure profiles between healthy people and patients with upper gut motility dysfunctions.

Development and content validity of a gastroparesis cardinal symptom index daily diary

Background  The Gastroparesis Cardinal Symptom Index (GCSI) is a patient‐reported outcome for gastroparesis using a two‐week recall period. To minimize potential patient recall effects, a daily diary version of the GCSI (GCSI‐DD) was developed.

Review: Functional dyspepsia

Dyspepsia is a common term used for a heterogeneous group of abdominal symptoms. Functional dyspepsia (FD) is the focus of this review. The 2006 Rome III criteria defined FD and its subgroups, postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). FD is a very common condition with a high prevalence throughout the world, adversely affecting the quality of life of patients. The pathophysiology of FD has been under investigation during the past two decades. Multiple mechanisms such as abnormal gastric emptying, visceral hypersensitivity, impaired gastric accommodation, and central nervous system factors are likely involved. Several tests are available for the assessment of various physiologic functions possibly involved in the pathogenesis of FD, and some of these could be used in clinical practice, helping to understand the abnormalities underlining patients’ complaints. Currently, the possibilities of pharmacological therapy for FD are still limited, however, experience of using prokinetics, tricyclic antidepressants, selective serotonin-reuptake inhibitors (SSRIs), proton-pump inhibitors (PPIs), and several alternative techniques has been accumulated. The different combinations of alterations in physiologic gastrointestinal and central nervous system functions result in the very heterogeneous nature of FD so combined approaches to these patients could be beneficial in challenging cases.

Effects of 5‐HT3 antagonism on postprandial gastric volume and symptoms in humans

Alosetron reduces symptoms of dyspepsia, but the physiological basis for the symptomatic benefit is unclear.