Role of the proximal and distal stomach in mixed solid and liquid meal emptying.

The role of the proximal and distal stomach in the emptying of solids and liquids from the stomach remains unclear. We have used a dual isotope technique to quantify proximal and distal stomach emptying of a solid (100 g of 99mTc labelled liver/ground beef) liquid (either 200 ml of normal saline (eight subjects) or 25% dextrose (seven subjects) labelled with 113mIn-diethylenetriaminepenta-acetic acid) mixed meal. A manometric catheter simultaneously measured antral, pyloric, and duodenal motor activity. The liquid component dispersed rapidly throughout the stomach and emptied after a minimal lag period. The emptying of the 25% dextrose was delayed compared with the saline. This delay was associated with increased retention of the liquid in the distal stomach, a significant increase in localised phasic pyloric contractions, and a suppression of antral contractions. The solid component initially resided wholly within a proximal stomach reservoir area. Solids then redistributed from proximal to distal stomach during the emptying of liquid from the stomach. Dextrose delayed gastric emptying of solids compared with saline by increasing the solid lag period and retention in the proximal stomach. There was no significant difference between saline and dextrose meals in the distal stomach retention of solid or in the linear rate of emptying after the lag period. We conclude that, contrary to general opinion, the proximal stomach plays an important role in the control of gastric emptying of solids while the distal stomach is important in the emptying of nutrient liquids.     

Gastric emptying in normal subjects--a reproducible technique using a single scintillation camera and computer system

The gastric emptying of a mixed solid and liquid meal was assessed in 24 normal subjects using a single camera/computer system which allowed continuous monitoring of both solids and liquids. It was shown that variation in tissue attenuation caused by the changing depth of radionuclide within the stomach accounted for large errors in the measurement of gastric emptying (alteration in 50% emptying time of up to 65%). A technique for the correction of attenuation is described which used factors derived from a lateral image of the stomach. In all subjects, solid emptying was slower than liquid emptying and was characterised by a delay (lag period) which was followed by linear emptying. Liquid emptying usually followed a single exponential pattern. The effect of physiological changes induced by increasing the calorie content of the liquid component of the meal was assessed by giving either water, 10% dextrose or 25% dextrose. Liquid emptying was slowed and the lag period of solid was prolonged as the calorie content increased. Reproducibility was assessed in 19 subjects. For the three groups studied (water, 10% dextrose, 25% dextrose) the day-to-day variation in gastric emptying was not significant for any measured parameter, while statistically significant differences were present in solid and liquid emptying between subjects and groups.     

Dietary caloric density and osmolality influence gastroesophageal reflux in infants

In a group of 19 infants being evaluated for gastro-esophageal reflux, we investigated the effects of various carbohydrate solutions (glucose polymers, 5% dextrose in water, and 10% dextrose in water) on the rate of postcibal gastroesophageal reflux during the first 2 h after a test feeding. The high-osmolality feeding (10% dextrose in water) produced significantly more postcibal gastroesophageal reflux over the entire 2-h interval. The major difference occurred in the second postcibal hour when the amount of gastroesophageal reflux was persistently high for 10% dextrose in water in contrast to the other feedings. We speculate that more rapid gastric emptying of low-osmolality solutions may account for these differences. Clear liquid feeding composition should be standardized during pH testing. Low-osmolality glucose polymer solutions may be more easily tolerated by infants with gastro-esophageal reflux who require carbohydrate or fluid supplements.     

Relationship between the effects of cisapride on gastric emptying and plasma glucose concentrations in diabetic gastroparesis

BACKGROUND/AIMS: The effect of erythromycin on gastric emptying is attenuated during hyperglycaemia. The aim of this study was to determine in patients with diabetic gastroparesis whether the effect of cisapride on gastric emptying of solids and liquids is influenced by the plasma glucose concentration. METHODS: Nineteen patients with type 1 diabetes mellitus, who had delayed gastric emptying of solids and/or liquids, were studied. On 2 separate days, each patient received cisapride (20 mg) or placebo orally 60 min before scintigraphic measurement of gastric emptying of a mixed solid (ground beef) and liquid (dextrose) meal. The plasma glucose concentrations were measured at -5, 30, 60, 90, and 120 min during each gastric emptying measurement. RESULTS: Cisapride accelerated both solid (retention at 100 min 43 +/- 4 vs. 69 +/- 4%, p < 0.001) and liquid (T50 27 +/- 2 vs. 39 +/- 2 min, p < 0.001) gastric emptying. The mean plasma glucose level was not significantly different after placebo when compared with cisapride (19.5 +/- 1.1 vs. 18.2 +/- 1.0 mmol/l). The change in the 50% emptying time (T50) for liquid, but not solid, emptying was related (r = 0.55, p = 0.01) to the change in the plasma glucose AUC from 0 to 30 min between the placebo and cisapride tests, i.e., the acceleration was greater if the plasma glucose concentration was relatively less during the gastric emptying test performed on cisapride. CONCLUSION: The effect of cisapride on gastric emptying, at least that of liquids, in patients with diabetic gastroparesis appears to be dependent on the plasma glucose concentration.     

Effects of meal composition on gallbladder and gastric emptying in man

Cholecystogastric scintigraphy, utilizing [^99mTc]HlDA to label the gallbladder contents and [¹¹¹In]DTPA to label different meals, was utilized to determine the relationships between gallbladder and gastric emptying after meals of differing composition. Gallbladder emptying was determined in response to a multicomponent meal and to monocomponent fat, carbohydrate, and protein meals and in response to isotonic and hypertonic dextrose and isotonic and hypertonic saline. Also, the gallbladder emptying responses to equivalent multicomponent solid and liquid meals were compared. Significant gallbladder emptying was observed in response to the multicomponent meal and the monocomponent fat, carbohydrate, and protein meals. The most rapid and complete gallbladder emptying was seen with the multicomponent meal and the monocomponent fat meal. Significant gallbladder emptying was stimulated, not only by isotonic and hypertonic dextrose, but also by hypertonic saline. The gallbladder emptied more rapidly after a liquid than after a solid meal.     

Rapid gastric emptying, rather than delayed gastric emptying, might provoke functional dyspepsia

It has been suggested that there could be three possible mechanisms of gastric dysfunction in patients with FD: (i) delayed gastric emptying, (ii) impaired gastric accommodation of food intake, and (iii) hypersensitivity to gastric distention. Postprandial fullness seems to be the most severe symptom in patients who report aggravation of their symptoms after meals. Therefore, it has been assumed that delayed gastric emptying and consequent prolonged antral distension could reduce hunger, increase satiety, and even cause gastric discomfort, all of which would pose a significant barrier to adequate nutrition. We previously reported that postprandial water intake inhibits gastric antral motility along with an increase of cholecystokinin (CCK) in normal subjects. We assumed that the rapid increase of CCK after water intake was initiated by a feedback mechanism related to the inflow of fatty chyme into the duodenum that inhibits gastric antral activity. This duodeno-gastric interaction is known as the "duodenal break." We also reported that total gastric emptying was more rapid after the intake of a high-viscosity liquid meal than after a low-viscosity meal, because the low-viscosity liquid meal inhibits gastric emptying after rapid initial inflow into the duodenum. Considering these results, we hypothesized that rapid gastric emptying, rather than delayed gastric emptying, could be a cause of FD. In some patients with postprandial distress syndrome (PDS), we have found a significant correspondence between PDS-related dyspepsia and accelerated gastric emptying in the early postprandial period. It is worth emphasizing that the duodenum and the duodeno-gastric interaction (duodenal break) could have an important role in the pathophysiology of FD. We consider that rapid gastric emptying might be a more important factor than delayed gastric emptying in patients with FD.     

Gastric motility measurement by MRI

The motor mechanisms associated with gastric emptying of nutrient liquids are unclear. Gastric emptying and motility were determined in seven healthy volunteers using an MRI technique following ingestion of 500 ml of (1) 10% and (2) 25% dextrose labeled with 1 mM Gd-DOTA. Emptying was determined with transaxial scans and motility during fast coronal scans 1.2 sec apart. Emptying was slower after ingestion of 25% dextrose. Following both meals, proximal gastric diameter remained relatively constant, while antral contractile frequency and depth varied markedly. These variations were greater after 10% dextrose. These studies suggest that antral motility changes contribute to slowing of gastric emptying by nutrient meals.     

Cold pain prolongs gastric emptying of liquid but not solid meal: an electrical impedance tomography (EIT) study

Stressful stimuli are reported to affect gastric emptying. However, methods for measuring gastric emptying are, in themselves, stressful. Electrical impedance tomography (EIT) is a method for measuring gastric emptying noninvasively. We used EIT to measure gastric emptying of liquid and solid meals to determine the effect of cold pain stress on gastric emptying. EIT (DAS-01P APT system; University of Sheffield, UK) was carried out in six healthy women (age, 21.6 ± 0.4 [mean ± SD] years) who had ingested a liquid (potage, 263 g; 139 kcal) or solid (beef patty, 205 g; 435 kcal) test meal. Cold pain stimuli consisted of repeated immersions of the subject's non-dominant hand into ice water (4°C) for 1 min, with a 15-s recovery period between immersions, for a total of 20 min. For the control stimulus, water at 37°C was used. The cold pain stimulus was applied immediately after the ingestion of a test meal. All studies were carried out randomly in each subject at intervals of more than 1 week. With cold pain, the half emptying time of the liquid meal was significantly greater than that with the control stimulus (47.6 ± 26.1 min vs 28.1 ± 10.8 min, P < 0.05). For the solid meal, the half emptying time did not differ between stimuli (101.9 ± 44.8 min with cold pain vs 92.6 ± 30.5 min with control stimulus). There were no significant differences in lag time between the liquid and solid meals. Cold pain stress delayed gastric emptying of liquid but not solid meals. Received: September 28, 1999 / Accepted: February 25, 2000     

A longitudinal study of gastric emptying and upper gastrointestinal symptoms in patients with diabetes mellitus

PURPOSE: To evaluate the natural history of gastric emptying and upper gastrointestinal symptoms in patients with diabetes mellitus. SUBJECTS AND METHODS: We enrolled 20 patients (6 men, 14 women) with diabetes mellitus (16 with type 1 diabetes, 4 with type 2 diabetes). Each had measurements of gastric emptying of a solid (100 g of ground beef) and liquid (150 mL of 10% dextrose) meal using scintigraphy, glycemic control (glycosylated hemoglobin [HbA(1c)] and mean blood glucose levels), upper gastrointestinal symptoms, and autonomic nerve function at baseline and after a mean (+/- SD) of 12.3 +/- 3.1 years of follow-up. RESULTS: There were no differences in mean gastric emptying of the solid component (retention at 100 minutes at baseline: 56% +/- 19% vs. follow-up: 51% +/- 21%, P = 0.23) or the liquid component (time for 50% to empty at baseline: 33 +/- 11 minutes vs. follow-up: 31 +/- 12 minutes, P = 0.71) during follow-up. Mean blood glucose (17.0 +/- 5.6 mmol/L vs. 13.8 +/- 4.9 mmol/L, P = 0.007) and HbA(1c) (8.4% +/- 2.3% vs. 7.6% +/- 1.3%, P = 0.03) levels were lower at follow-up. There was no difference in symptom score (baseline: 3.9 +/- 2.7 vs. follow-up: 4.2 +/- 4.0, P = 0.78). There was evidence of autonomic neuropathy in 7 patients (35%) at baseline and 16 (80%) at follow-up. CONCLUSION: In patients with diabetes mellitus, we did not observe any marked changes in either gastric emptying or upper gastrointestinal symptoms during a 12-year period.     

Gastric emptying of combined liquid-solid meals in healed duodenal ulcer

The gastric emptying rates of combined liquid and solid radioisotopically labeled meals in 47 healed duodenal ulcer subjects and 17 healthy control subjects are compared. No significant differences were found between the groups in emptying slopes and the emptying half-times or in the percent retention values at any of the counting intervals for either the liquid or solid meals. These results are compatible with the observation that the rapid gastric emptying in many patients with duodenal ulcer is associated with the disease and that healing results in a return to normal gastric emptying rates. However, since gastric empyting rates during active ulceration were not determined in our patients, a more definitive interpretation awaits a study comparing emptying rates obtained during and after healing of active ulceration in the same patient.The authors wish to acknowledge the support of the Veterans Administration Medical Research Service and the G.D. Searle Co. for providing support for this study.     

Mechanisms governing the biphasic pattern of gastric emptying after truncal vagotomy and pyloroplasty.

The pattern of gastric emptying after truncal vagotomy and drainage is usually biphasic. An early rapid phase is followed by a characteristically abrupt transition to slow emptying. The mechanisms responsible for this pattern were studied in six dogs with truncal vagotomy and pyloroplasty, fitted with a proximal duodenal cannula. Gastric emptying was measured using gamma camera imaging of a radiolabelled 15% dextrose test meal. Sixty one hour studies were done using five designs. (1) With the cannula closed gastric emptying was initially rapid, followed by stasis (emptying at 15 min - 32% (5.3), 60 min - 34% (4.8); mean (SE)). (2) With the cannula open emptying was very rapid (15 min - 76% (4.2) p less than 0.001, 60 min - 88% (2.6) p less than 0.001 ANOVA). (3) Distal duodenal instillation of isotonic saline, at a rate equivalent to gastric emptying with the cannula closed, did not retard this rapid emptying (15 min - 78% (10.6), 60 min - 90% (5.4)). (4) With duodenal instillation of 15% dextrose, gastric emptying remained faster than in studies without diversion (15 min - 50% (7.0) NS, 60 min - 65% (6.8) p less than 0.01), but was slower than during diversion alone (p less than 0.05). (5) Finally, duodenal instillation of 15% dextrose before administration of the test meal produced slower initial emptying without subsequent stasis (15 min - 24% (4.5), 60 min - 47% (10.6)), although the amounts emptied were not significantly different from those with the cannula closed. These results indicate that after truncal vagotomy and pyloroplasty small bowel resistances play a significant role in controlling gastric emptying. Osmoreceptor responses persist after truncal vagotomy, but sympathetic inhibitory responses to small bowel distension are not involved in the regulatory process.     

Canine resistances to gastric emptying of liquid nutrients after ulcer surgery

In two groups of dogs, we studied average rates of gastric emptying of 0.15 M NaCl, 0.6 M glucose, or 0.04 M oleate liquid meals while gastric pressures were controlled by a barostat and compared this emptying to spontaneous gastric emptying of the same three meals. In the first group of dogs, this comparison was made before and after truncal vagotomy+pyloroplasty (TVP); and in the second group, before and after antrectomy, first with gastroduodenostomy (A-BI) and then with Roux-Y bypass (A-RY). Under barostatically controlled gastric pressures, gastric emptying of oleate and glucose remained slower than emptying of saline before as well as after TVP or A-BI and A-RY. However, all operations accelerated initial spontaneous emptying, compressing differences between half-emptying times of the three meals. We conclude postfundic resistances remain after TVP or antrectomy but may act too late to alter rapid initial emptying.This work was supported by research funds from the Veterans Administration and by funds from the National Institutes of Health (AM 19182 and AM 17328). Mr. Williams (Department of Surgery, University of Leeds, England) performed this work under a Fullbright International Fellowship.     

Scintigraphic measurement of gastric emptying and ultrasonographic assessment of antral area: relation to appetite.

BACKGROUND: Ultrasound measurement of gastric emptying has potential advantages over scintigraphy, but there is little information about its accuracy. AIMS: The relation between ultrasonographic measurements of antral area and (a) scintigraphic measurements of gastric emptying and intragastric distribution of liquids (b) postprandial satiation, were evaluated. SUBJECTS: Seven normal volunteers were studied. METHOD: Each subject drank 75 g dextrose dissolved in 350 ml of water (300 kcal) or beef soup (20 kcal), both labelled with technetium-99m sulphur colloid on separate days and had measurement of gastric emptying by scintigraphy and ultrasound. RESULTS: Scintigraphic and ultrasound 50% emptying times (T50s) were comparable and longer (p < 0.001) for dextrose than soup mean (SEM) (dextrose 107 (16) min v 108 (18) min, soup 24 (4) min v 23 (5) min). There were close correlations between scintigraphic and ultrasound T50s (dextrose r = 0.94, p < 0.005, soup r = 0.97, p < 0.001) and between the time at which the distal stomach content decreased from its maximum value by 50% (measured scintigraphically) and the ultrasound T50 (dextrose r = 0.95, p < 0.005, soup r = 0.99, p < 0.0001). In contrast, there was no significant relation between the distal stomach content when expressed as a percentage of the maximum content in the total stomach and the ultrasound T50. After dextrose, fullness was related (r = 0.92, p < 0.01) to the postprandial increase in antral area measured by ultrasound. CONCLUSIONS: Ultrasound measurements of gastric emptying are: (a) of comparable sensitivity to scintigraphy in quantifying emptying of both low and high nutrient liquids (b) correlate with postprandial satiation, suggesting that the latter may be mediated by antral distension.     

Disturbed gastric emptying in the short bowel syndrome. Evidence for a 'colonic brake'.

Gastric emptying of liquid (orange juice containing technetium-99m (99mTc) labelled antimony sulphide colloid) and solid (570 kcal pancake containing 0.5 mm resin microspheres labelled with Indium-111 (111-In)) was measured in seven patients with jejunum and no colon (jejunal lengths 30-160 cm), six patients with jejunum in continuity with the colon (jejunal length 25-75 cm), and in 12 normal subjects. In patients with no colon early emptying of liquid was rapid (median 25% emptying: 7 v 25 min, no colon v normal, p < 0.05); early gastric emptying of solid was rapid in two (each with less than 100 cm jejunum) and normal in the other five. Gastric emptying of liquid and solid for patients with jejunum in continuity with the colon was normal for the first three hours. There was increased liquid and solid retained in the stomach at six hours in both groups of patients (p < 0.01). Small bowel transit time was faster than in normal subjects for liquid in both groups of patients (p < 0.05) and for solid in those with no colon (p < 0.05). Rapid gastric emptying of liquid may contribute to the large stomal output in patients with a high jejunostomy. Preservation of the colon after a major small intestinal resection exerts a braking effect on the rate of early gastric emptying of liquid.     

Effect of ethanol upon gastric emptying.

The effect of ethanol upon gastric emptying in healthy human subjects was studied by measuring the gastric emptying rates of three 750 ml meals, the osmolalities, energy densities, and pH of which were similar. Meal A, which contained 80 ml alcohol, emptied more rapidly than meal B, which contained 40 ml ethanol and 63.3 g dextrose; and meal B emptied more rapidly than meal C, which contained 126.6 g dextrose but no ethanol. The slower rate of emptying of the dextrose meal (C) was not due to an increased gastric secretory rate, as serial measurements of gastric pH were substantially and significantly higher with this than with the other two meals; nor was it due to a greater degree of duodenogastric reflux, as serial measurements of gastric bile acid concentrations were similar for the three meals. We conclude that the duodenal osmoreceptor mechanism is relatively insensitive to ethanol; that the relationship between energy density and gastric emptying rate does not hold in the case of ethanol; and that the gastro-oesophageal reflux which occurs in response to ethanol is not due to impairment of gastric emptying.     

Biphasic solid and liquid gastric emptying in normal controls and diabetics using continuous acquisition in LAO view

The purpose of this study was to investigate the various phases of gastric emptying using a dual-isotope liquid-solid meal ([^99mTc]Sc egg sandwich and [¹¹¹In]DPTA in water) and continuous acquisition in the left anterior oblique view. The study groups consisted of 10 normal controls and 20 diabetics with symptoms suggestive of diabetic gastroparesis. Solid-phase emptying in both groups almost always had a lag phase followed by linear emptying. Liquid-phase emptying was biexponential in 4/10 normals and 12/20 diabetics, with a short early rapid emptying rate (meanT1/2=48 min in normals and 79 min in diabetics). Solid emptying was delayed in 10, normal in eight, and rapid in two diabetics. Liquid emptying was delayed in 9/10 diabetics who had delayed solid emptying. Diabetics as a group had a significantly delayed solid lag phase (P<0.025), rate of emptying (P<0.05) and percent emptying at 90 min (P<0.025) compared to normal controls. Diabetic liquid emptying was also significantly delayed (P<0.025). The second component of liquid emptying strongly correlated with the solid rate of emptying (r=0.826 in normals and 0.855 in diabetics). Continuous acquisition of gastric emptying studies in the LAO view has allowed us to better define the various phases of solid and liquid gastric emptying.     

Abnormal pattern of gastric emptying of liquid in chronic duodenal ulcer

Gastric emptying was measured in 12 patients with chronic duodenal ulceration and compared with the results from 10 healthy volunteers. The test meal of 300 ml 15% dextrose, labelled with 99mTc-DTPA, was ingested in increments over 6 min. Gamma camera imaging proceeded over 30 min, with a 1-min frame time. A direct correction was applied for the fraction emptying into the small bowel during the ingestion period. Gastric emptying at 6 min was significantly greater in the group with duodenal ulcer (14.4 +/- 2.7% vs. 4.2 +/- 0.9%: mean +/- SEM, p less than 0.01). From this time onwards there were no significant differences in the rates of gastric emptying. These results suggest that chronic duodenal ulcer is associated with an abnormal pattern of gastric emptying of liquid, characterised by an initial rapid phase.     

Progression of changes in gastric emptying of hypertonic liquids after proximal gastric vagotomy

Gastric emptying rates of hypertonic (10%) dextrose liquid meals were studied in five dogs before, and 3, 6, and 12 months after proximal gastric vagotomy (PGV) without drainage. The purpose of this study was to determine if operation-related changes in emptying rates normalized or became more disparate during the year after PGV. An increased rate of emptying during the first 5 min after ingestion was seen at 3 months after PGV, which significantly increased (P<0.025) after 6 and 12 months. The remainder of the meal after PGV emptied at a regulated exponential rate unchanged throughout the postoperative year from its preoperative rate. Total volumes of gastric aspirate at four intervals after meal ingestion did not significantly change across the four test periods in respect to endogenous secretion or pH acidity.Supported by The Veterans Administration.     

Gastric emptying rate after gastric bypass and gastroplasty

Fifty-seven morbidly obese patients were randomized into two surgical treatment groups, gastric bypass (n = 29) and gastroplasty (n = 28). Studies of the gastric emptying with radionuclide-labelled food were performed preoperatively (12 patients) and postoperatively at 2 months (28 patients) and 12 months (49 patients). Pouch emptying after gastric bypass was slower at 2 months than at 12 months. After gastroplasty the emptying rate was the same at 2 and 12 months and the same as that of gastric bypass at 12 months. A statistically significant correlation between stoma diameter and emptying rate was seen 1 year after gastroplasty but not after gastric bypass. No correlation between emptying rate and weight loss was shown in either group. Differences in the mechanisms of action between these two methods are apparent and are discussed.     

Influence of food and marker length on gastric emptying of indigestible radiopaque markers in healthy humans

A simple, noninvasive radiographic method was used to investigate the influence of food and of marker length on gastric emptying of indigestible solids. Ten healthy human subjects who had fasted for 12 h exhibited more rapid emptying when solid radiopaque markers were ingested with water than they did when markers were ingested with a 400-kcal solid and liquid meal. Mean (+/- SE) emptying of markers that were 10 mm in length averaged 55% +/- 15%, 97% +/- 3%, and 100% 1, 2, and 4 h after ingestion of the markers with water, compared with 4% +/- 2%, 32% +/- 11%, and 64% +/- 12% emptying 1, 2, and 4 h after ingestion of markers with the meal (p less than 0.05). Ingestion of a second and third test meal significantly prolonged gastric emptying of indigestible markers (p less than 0.05). No significant difference in emptying of the 10- and 2-mm markers from the stomach was detected. These experiments indicate that gastric emptying of indigestible solids in humans is strongly influenced by food intake, but not by the particle lengths studied.