Abdelnaem, Nada

ABSTRACT Background Gastric emptying (GE) scintigraphy with 4‐h imaging and a radiolabeled chicken egg‐based meal (320 kcal, 30% fat) is the standard test for gastroparesis at Mayo Clinic, with an intraindividual coefficient of variation (COV intra ) of 23.8% for GE half emptying time (T 1/2 ). Alternative meals for patients with dietary restrictions, including egg allergies or vegan diets, are lacking, limiting test accessibility. The study aimed to establish a vegan, lactose‐, nut‐, and gluten‐free meal with similar caloric and fat content to the egg meal and to assess its performance in GE studies. Methods In Vitro: 99m Tc binding to egg meal over 4 h was compared to a calorically and nutritionally similar vegan alternative, JUST Egg, using a validated in vitro model simulating gastric conditions of pH, pepsin, and stirring. In Vivo: 10 healthy participants underwent randomized crossover GE scintigraphy with standard and vegan meals, spaced ≥ 3 days apart to measure GE% at 2 h, 4 h, and GE T 1/2 . Group comparisons and variance analysis included Rank Sum tests and Bland–Altman plots. Key Results In Vitro: A strong correlation ( R = 0.975, p ‐value < 0.01) between 99m Tc binding in the egg and vegan egg models was observed. Minimal variance (< 10%) was recorded at all time points. In Vivo: GE at 4 h and GE T 1/2 showed non‐statistically significant mean differences, < 2% and < 10 min respectively, between both meals. The intra‐individual variability was 18.8%. Conclusions and Inferences The vegan meal demonstrated in vitro stability, in vivo performance comparable to the egg meal, and a COV intra of 18.8%, which was lower than the 23.8% reported in repeat egg meal GE studies. Trial Registration ClinicalTrials.gov number NCT06991036 ( https://clinicaltrials.gov/study/NCT06991036?term=NCT06991036&rank=1 )

ABSTRACTIntroductionUpper and lower gastrointestinal (GI) dysfunctions frequently coexist, potentially mediated by gastrocolonic or cologastric neural reflexes. This study aims to assess the prevalence of impaired gastric accommodation (GA) and delayed gastric emptying (GE) among patients with slow colonic transit (CT), dyssynergic defecation (DD), and to evaluate relationships between CT or DD with impaired GA and delayed GE.MethodsWe reviewed records of 178 adult patients at Mayo Clinic (2005–2025) with documented slow CT or DD (respectively based on scintigraphy and high‐resolution anorectal manometry [ARM] and balloon expulsion [BE]) who underwent 99mTc‐SPECT measurement of GA and scintigraphic GE of 320‐kcal, 30% fat egg meal. Slow CT was defined by geometric center (GC) at 48 h < 2.1 for males and < 1.9 for females. Abnormal GA ratio was assessed as reduced < 2.62 or increased > 3.85, and delayed GE % < 75% at 4 h. Correlations were assessed using Spearman rank test.ResultsReduced GA was found in 23.7% with DD and 26.7% with slow CT, while increased GA was observed in 30.1% and 24.4%, respectively. Delayed GE was present in 20.5% DD patients and 35.6% slow CT patients. GC 48 h and 24 h were positively correlated with GE% 4 h (Rs = 0.279, and Rs = 0.294 respectively, both p < 0.001) suggesting slow CT retards GE. GC 48 h was moderately correlated with resting anal pressure (Rs = 0.259, p < 0.001) and negatively with the rectoanal pressure gradient (Rs = −0.166, p = 0.027). No significant correlations were observed between CT and GA.ConclusionSlow CT is associated with slower GE, suggesting cologastric reflex inhibition, but not with GA. There is a high prevalence of impaired GA and delayed GE in slow CT and DD.

ABSTRACT Background In healthy controls, higher gastric accommodation (GA) was associated with slower gastric emptying (GE) of solids. Aims In patients with gastroparesis: (1) To investigate the association between GA and GE of solids. (2) To assess the prevalence of abnormally high GA. Methods An electronic medical records (EMR) review (2010–2024) was conducted on 745 adult patients with measured GA following 300 kcal Ensure using SPECT, and scintigraphy‐based GE of solids (320 kcal, 30% fat, egg meal). Among these patients, 284 had gastroparesis (GE < 25% emptied at 2 h or < 75% emptied at 4 h). Spearman correlation analysis examined associations between GA volume or ratio and GE at 1, 2, and 4 h, and GE T 1/2 . Results Weak positive correlations were observed between GA volume and GE of solids % at 1 and 2 h (respectively R s = 0.148, p = 0.0234, and R s = 0.121, p = 0.042). In addition, there was a correlation between GA ratio and GE of solids % at 2 h ( R s = 0.143, p = 0.0160). However, there were no significant correlations of GA with GE % at 4 h or GE T 1/2 . Among the 284 patients with gastroparesis, we had documented increased GA, assessed by postprandial minus preprandial gastric volume (> 640 mL), in 7.75%, and increased GA by GA ratio > 3.85 in 22.9%. Conclusions Among patients with gastroparesis, higher GA is associated with accelerated GE of solids in the first 2 h, though the effect size is small. There is no significant effect on delayed GE at 4 h or GE T 1/2 .