Relationship between intragastric meal distribution, gastric emptying, and gastric neuromuscular dysfunction in chronic gastroduodenal disorders

Background: Chronic gastroduodenal symptoms arise from heterogeneous gastric motor dysfunctions. This study applied multimodal physiological testing using gastric emptying scintigraphy (GES) with intragastric meal distribution (IMD) and Gastric Alimetry body surface gastric mapping (BSGM) to define motility and symptom associations. Methods: Patients with chronic gastroduodenal symptoms underwent simultaneous supine GES and BSGM with a 30 m baseline, 99mTC-labeled egg meal, and 4 h postprandial recording. IMD (ratio of counts in the proximal half of the stomach to the total gastric counts) was calculated immediately after the meal (IMD0), with < 0.568 defining abnormal IMD. BSGM phenotyping followed a consensus approach, based on normative spectral reference intervals. Results: Among 67 patients (84% female, median age 40 years, median BMI 24 kg/m²), median IMD0 was 0.76 (IQR: 0.69–0.86) with 5 (7.5%) meeting abnormal IMD criteria. Delayed gastric emptying (n = 18) was associated with higher IMD0 (median 0.9 vs. 0.7, p = 0.004). On BSGM, 15 patients had abnormal spectrograms (5 [7.5%] high frequency and 10 [14.9%] low rhythm stability and/or amplitude); and in these patients, higher IMD0 (proximal retention) strongly correlated to delayed BSGM meal responses (R = −0.71, p = 0.003). Lower IMD, indicating antral distribution, correlated with higher gastric frequencies (R = −0.27, p = 0.03). BSGM abnormalities paired with abnormal IMD were associated with worse dyspeptic symptoms. Conclusion: Proximal retention of food as assessed by IMD correlated with delayed emptying, and in the presence of neuromuscular spectral abnormalities (abnormal frequencies or rhythms), delayed motility responses on BSGM. Patients with multiple motor abnormalities experience worse dyspeptic symptoms.