Gastric accommodation: Physiology, diagnostic modalities, clinical relevance, and therapies

Assessing impaired gastric accommodation in children with functional constipation using the water load test

BACKGROUND

This study aimed to evaluate gastric accommodation in pediatric patients with functional constipation using the water load test.

METHOD

This was a cross-sectional case-control study. Herein, the water load test results of children aged >4 years with functional constipation referred to a Pediatric Gastroenterology Outpatient Clinic (functional constipation group) were compared with those of a control group (without functional constipation or chronic abdominal pain) recruited from two public schools. Clinical manifestations outlined in the Rome IV criteria were used to diagnose functional constipation. Water load tests were performed after 3 h of fasting. For the test, the participants were asked to drink as much water as possible in 3 min.

KEY RESULTS

A total of 36 patients and 77 students were included in the functional constipation and control groups, respectively. There was no significant difference in age between the groups (8.6 ± 2.3 years and 8.8 ± 1.8 years in the functional constipation and control groups, respectively). The water load test showed intake volumes of 390 ± 245 mL and 528 ± 219 mL in the functional constipation and control groups, respectively (p = 0.001). The maximum volume in the water load test correlated with the 24 h daily intake of energy (rS = +0.42, p = 0.012), protein (rS = +0.48, p = 0.004), and water (rS = +0.39, p = 0.020) only in the group with functional constipation.

CONCLUSIONS & INFERENCES

According to the water load test, gastric accommodation was impaired in children with severe functional constipation. The impairment of gastric accommodation in children with severe functional constipation is related to food intake.

Randomized, crossover trial: comparing the effects of standardized egg-white meal and Vital® on global gastric emptying parameters and intragastric meal distribution in healthy Asian participants

BACKGROUND AND AIM

Measurements of gastric emptying and accommodation for alternative test-meal protocol during gastric emptying scintigraphy (GES), such as high-calorie nutrient drinks, are not fully established. We aimed to compare the effects of standardized egg-white meal (EWM) versus high-calorie nutrient drink (Vital®; Abbott Laboratories) on global GES parameters and intragastric meal distribution at immediate scan (IMD0h).

METHODS

Of 84 screened participants, 60 asymptomatic healthy Asian population (38 females; 24.0 ± 1.5 years; 23.8 ± 2.6 kg/m2) were recruited in this 2 × 2 (AB/BA) crossover trial. Participants were randomized to a 4-h GES with 99mTc-radiolabeled EWM (~255.8 kcal), followed by a 200 mL Vital® (300 kcal), or vice versa, separated by a 2-week washout period. Global meal retention (GMR), power-exponential model emptying parameters (half-emptying [T1/2], lag phases [Tlag2%, Tlag5%, Tlag10%]), and IMD0h were determined and compared.

RESULTS

GMRs for both test meals were within the international standard references for solid GES. Compared to EWM, Vital® exhibited significantly lower GMRs (faster emptying) from 0.5 to 3 h (all P < 0.001) but comparable at 4 h (P = 0.153). Similar observations were found for the model-based T1/2 and the different Tlag thresholds (all P < 0.001). Furthermore, IMD0h was found to be lower with Vital®, indicating lower gastric accommodation (faster antral filling) immediately post-ingestion (P < 0.001). Both test meals showed significant moderate-to-strong positive associations at the late-phase GE (GMR 2-4 h, T1/2) (all P < 0.05).

CONCLUSIONS

Overall, Vital® is an acceptable alternative test meal to the EWM for GES; however, exercise caution when interpreting early-phase GE. The normative values for global GES parameters and IMD0h are also established.

Avoidant/restrictive food intake disorder prevalence is high in children with gastroparesis and functional dyspepsia

BACKGROUND

Avoidant/restrictive food intake disorder (ARFID) prevalence in children with gastroparesis (Gp) and/or functional dyspepsia (FD) is unknown. We aimed to identify ARFID prevalence and trajectory over 2 months in children with Gp, FD, and healthy children (HC) using two screening questionnaires. We also explored the frequency of a positive ARFID screen between those with/without delayed gastric emptying or abnormal fundic accommodation.

METHODS

In this prospective longitudinal study conducted at an urban tertiary care hospital, patients ages 10-17 years with Gp or FD and age- and gender-matched HC completed two validated ARFID screening tools at baseline and 2-month follow-up: the Nine Item ARFID Screen (NIAS) and the Pica, ARFID, and Rumination Disorder Interview-ARFID Questionnaire (PARDI-AR-Q). Gastric retention and fundic accommodation (for Gp and FD) were determined from gastric emptying scintigraphy.

KEY RESULTS

At baseline, the proportion of children screening positive for ARFID on the NIAS versus PARDI-AR-Q was Gp: 48.5% versus 63.6%, FD: 66.7% versus 65.2%, HC: 15.3% versus 9.7%, respectively; p < 0.0001 across groups. Of children who screened positive at baseline and participated in the follow-up, 71.9% and 53.3% were positive 2 months later (NIAS versus PARDI-AR-Q, respectively). A positive ARFID screen in Gp or FD was not related to the presence/absence of delayed gastric retention or abnormal fundic accommodation.

CONCLUSIONS & INFERENCES

ARFID detected from screening questionnaires is highly prevalent among children with Gp and FD and persists for at least 2 months in a substantial proportion of children. Children with these disorders should be screened for ARFID.

Relationships among intragastric meal distribution during gastric emptying scintigraphy, water consumption during water load satiety testing, and symptoms of gastroparesis

Gastric emptying scintigraphy (GES) measures total gastric retention after a solid meal and can assess intragastric meal distribution (IMD). Water load satiety test (WLST) measures gastric capacity. Both IMD immediately after meal ingestion [ratio of proximal gastric counts after meal ingestion to total gastric counts at time 0 (IMD0)] and WLST (volume of water ingested over 5 min) are indirect measures of gastric accommodation. In this study, IMD0 and WLST were compared with each other and to symptoms of gastroparesis to gauge their clinical utility for assessing patients with symptoms of gastroparesis. Patients with symptoms of gastroparesis underwent GES to obtain gastric retention and IMD0, WLST, and filled out patient assessment of upper GI symptoms. A total of 234 patients with symptoms of gastroparesis were assessed (86 patients with diabetes, 130 idiopathic, 18 postfundoplication) and 175 (75%) delayed gastric emptying. Low IMD0 <0.568 suggesting initial rapid transit to the distal stomach was present in 8% and correlated with lower gastric retention, less heartburn, and lower volumes consumed during WLST. Low WLST volume (<238 mL) was present in 20% and associated with increased severity of early satiety, postprandial fullness, loss of appetite, and nausea. Low IMD0 is associated with less gastric retention and less heartburn. Volume of water consumed during WLST, while associated with IMD0, has associations with early satiety, postprandial fullness, loss of appetite, and nausea. Thus, IMD0 and WLST appear to overlap somewhat in their assessment of gastric physiology in adults with symptoms of gastroparesis but relate to different dyspeptic symptoms.NEW & NOTEWORTHY IMD0 and WLST were assessed for their clinical utility in assessing patients with symptoms of gastroparesis. Low IMD0 is associated with less gastric retention and less heartburn. Volume of water consumed during WLST, while associated with IMD0, has associations with early satiety, postprandial fullness, loss of appetite, and nausea. IMD0 and WLST appear to overlap somewhat in their assessment of gastric physiology in adults with symptoms of gastroparesis but relate to different dyspeptic symptoms.

Assessment and management of disorders of gut-brain interaction in patients with eating disorders

Disorders of gut-brain interaction (DBGI), also known as functional gastrointestinal disorders, are common in individuals with eating disorders, and may precede or perpetuate disordered eating. Understanding the pathophysiology of common gastrointestinal symptoms in DGBI can be important for the care of many patients with eating disorders. In this review, we summarize the literature to date on the complex relationship between DBGI and eating disorders and provide guidance on the assessment and management of the most common symptoms of DBGI by anatomic region: esophageal symptoms (globus and functional dysphagia), gastroduodenal symptoms (functional dyspepsia and nausea), and bowel symptoms (abdominal pain, bloating and constipation).

Gastric dysmotility and gastrointestinal symptoms in myalgic encephalomyelitis/chronic fatigue syndrome

BACKGROUND

Gastrointestinal symptoms are common in ME/CFS, but there is a knowledge gap in the literature concerning gastrointestinal motility features and detailed symptom description.

OBJECTIVE

In this study, we aimed to characterize gastric motility and gastric symptoms in response to a liquid meal.

METHODS

We included 20 patients with ME/CFS with abdominal complaints who were recruited to a double-blind randomized placebo-controlled trial of Rituximab. The patients of this sub study were examined with an ultrasound drink test, and gastrointestinal symptoms were evaluated using the Rome III questionnaire and Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS) questionnaire.

RESULTS

We found that patients commonly reported fullness/bloating (75%), abdominal pain (45%) and nausea (35%). Ultrasound measurements revealed lower proximal measurements of the stomach after a meal (p < 0.01) and larger fasting antral area (p = 0.019) compared to healthy controls. The patients had a stronger symptomatic response to the liquid meal compared to healthy controls regarding epigastric pain, discomfort and nausea (p < 0.05).Ninety percent of the patients reported bowel movement frequencies within the normal range but scored high on bowel habit dissatisfaction and life disruption.

CONCLUSION

The patients presented with fullness/bloating, nausea and epigastric pain, showed signs of impaired gastric accommodation and visceral hypersensitivity, showing that the gastrointestinal symptoms of ME/CFS patients are similar to functional dyspepsia.Key summary Gastrointestinal symptoms are common in ME/CFS, but there is a knowledge gap in the literature concerning gastrointestinal motility features and detailed symptom description. • In this study, patients with ME/CFS had signs of impaired gastric accommodation after a liquid meal. • Out of 20 patients, 15 patients reported fullness/bloating, 9 reported abdominal pain, and 7 reported nausea. The patients showed signs of visceral hypersensitivity on a drink test. • Our findings suggest that patients with ME/CFS share many similarities with patients with Functional Dyspepsia. The findings were not typical for Irritable Bowel Syndrome.

Imaging Review of Gastrointestinal Motility Disorders

The motor function of the gastrointestinal tract relies on the enteric nervous system, which includes neurons spanning from the esophagus to the internal anal sphincter. Disorders of gastrointestinal motility arise as a result of disease within the affected portion of the enteric nervous system and may be caused by a wide array of underlying diseases. The etiology of motility disorders may be primary or due to secondary causes related to infection or inflammation, congenital abnormalities, metabolic disturbances, systemic illness, or medication-related side effects. The symptoms of gastrointestinal dysmotility tend to be nonspecific and may cause diagnostic difficulty. Therefore, evaluation of motility disorders requires a combination of clinical, radiologic, and endoscopic or manometric testing. Radiologic studies including fluoroscopy, CT, MRI, and nuclear scintigraphy allow exclusion of alternative pathologic conditions and serve as adjuncts to endoscopy and manometry to determine the appropriate diagnosis. Additionally, radiologist understanding of clinical evaluation of motility disorders is necessary for guiding referring clinicians and appropriately imaging patients. New developments and advances in imaging techniques have allowed improved assessment and diagnosis of motility disorders, which will continue to improve patient treatment options. Online supplemental material is available for this article. ^©RSNA, 2022.

Simulating human gastrointestinal motility in dynamic in vitro models

The application of dynamic in vitro gastrointestinal (GI) models has grown in popularity to understand the impact of food structure and composition on human health. Given that GI motility is integral to digestion and absorption, a predictive in vitro model should faithfully replicate the motility patterns and motor functions in vivo. In this review, typical characteristics of gastric and small intestinal motility in humans as well as the biomechanical and hydrodynamic events pertinent to gut motility are summarized. The simulation of GI motility in the presently existing dynamic in vitro models is discussed from an engineering perspective and categorized into hydraulic, piston/probe-driven, roller-driven, pneumatic, and other systems. Each system and its representative models are evaluated in terms of their motility patterns, the key hydrodynamic characteristics concerning gut motility, their performance in simulating the key physiological events, and their ability to establish in vitro-in vivo correlations. Practical Application: The review paper provided useful information in the design of dynamic GI models and the simulation of human gastric and small intestinal motility which are important for understanding food and health.