Gastric electrical stimulation at proximal stomach induces gastric relaxation in dogs

Gastric electrical stimulation (GES) improves symptoms in patients with gastroparesis. However, the underlying mechanisms remain unclear. To determine if GES at proximal and distal stomach could affect the biomechanical properties of the stomach, thus contributing to the beneficial effect of GES. Four pairs of electrodes were implanted along the greater curvature of the stomach in seven dogs. Gastric tone and compliance was assessed with a barostat. Measurements were obtained randomly during control and proximal and distal stimulation (4 mA, 375 ms and 6/18 cpm). Data as mean or median (25-75th percentiles). Gastric compliance was not affected by proximal and distal GES. Gastric tone was significantly reduced during proximal GES: 82.0 (66.8, 89.1) mL vs control 49.7 (39.6,75.9) mL at 6 cpm (P = 0.016), and 90.6 (54.5, 117.9) mL vs control 62.8 (39.6, 75.9) mL at 18 cpm (P = 0.031). Tone was not affected by distal GES at 6 cpm: 95.8 (46.3, 106.7) mL vs control 75.2 (49.7, 86.1) mL (P = 0.47) and at 18 cpm: 80.4 (38.1, 170.3) mL vs control 62.8 (44.6, 156.3) mL (P = 0.44). Proximal GES induces gastric relaxation. This effect, if seen also in humans, may explain, in part, the symptomatic improvement associated with GES therapy in patients with gastroparesis.     

Gastric tone,volume and emptying after implantation of an intragastric balloon for weight control

Background The intragastric balloon, filled with air or liquid is used before elective bariatric surgery because its efficacy is limited. This might be the consequence of altered gastric functions. Therefore, we aimed to investigate, in an animal model, the changes in gastric motility and emptying induced by long‐term insertion of a balloon used for weight reduction. Methods Ten Göttingen mini‐pigs were allocated into two groups with and without an intragastric balloon for 5 months. Balloons were inserted under endoscopy during general anesthesia and were filled with 350 mL of air. Gastric emptying was evaluated by scintigraphy. Gastric volume was measured by single photon emission computed tomography and proximal gastric compliance obtained using an electronic barostat. Changes in vagal tone were assessed by heart rate variability (HRV). Key Results After balloon insertion, gastric volume was significantly increased (2047 ± 114.8 cm³ after vs 1674 ± 142.5 cm³ before insertion, P < 0.05). Gastric compliance was also larger in balloon group (219 ± 23.4 mL mmHg^?1 in balloon vs 168 ± 7.7 mL mmHg^?1 in control group). Gastric emptying was reduced after insertion of the balloon (T_1/2 = 204 ± 28.8 min vs 159 ± 25.4 before vs after insertion). High frequency components of the spectral analysis of HRV, representing vagal tone, were increased in balloon group. Conclusions & Inferences The proximal stomach was enlarged after the insertion of a balloon in the stomach as a consequence of an increased gastric compliance. This change in compliance was probably causative for a reduction in gastric emptying rate of solids. These alterations were associated with increased vagal tone.     

Correlation between gastric pH and gastro-oesophageal reflux contents: ambulatory pH-impedance monitoring results

Gastro-oesophageal reflux events should be related to gastric contents. The goal of this study was to determine the relationship between gastric pH and the nature of reflux events. Ambulatory oesophageal pH-impedance and gastric pH monitoring was performed in 41 patients [29 off and 12 on proton pump inhibitor (PPI) therapy] and 12 controls. The mean gastric pH was measured within 2 min around the reflux episodes, 10 cm below the cardia. Acid reflux events occurred more frequently at gastric pH <4 (89%) than non-acid reflux events (63%, P < 0.0001). Acid reflux events extended more frequently 15 cm above the lower oesophageal sphincter (LOS; 34%) than non-acid reflux episodes (24%, P = 0.005). Gastric pH was significantly lower during interprandial reflux events than during postprandial ones in the three groups (P < 0.001). A positive correlation was found between gastric pH and the nadir oesophageal pH during reflux events in the three groups: this correlation was more significant in patients on PPI therapy. We conclude that most acid and non-acid reflux episodes occur at acid gastric pH, as measured 10 cm below the LOS. This measure does not appear a good predictor of the pH of reflux events.     

Effects and mechanisms of long-pulse gastric electrical stimulation on canine gastric tone and accommodation

Gastric electrical stimulation (GES) has been applied to treat gastroparesis and morbid obesity. The aims of this study were to evaluate the sites of stimulation and the mechanisms of GES on gastric tone and accommodation. Gastric tone and accommodation were evaluated with a barostat in surgically prepared dogs. GES was applied at seven different locations, and gastric tone was assessed at each site. The effect of truncal vagotomy on gastric tone and accommodation and the role of the nitrergic pathway were also evaluated. We have found: 1) GES induced varying degrees of gastric relaxation at all tested locations in normal dogs; 2) Gastric volume was also significantly increased with GES in vagotomized dogs and the change tended to be lower than that of normal animals; 3) Gastric accommodation was reduced during GES in both the normal and vagotomized dogs and the reduction tended to be more in the vagotomized animals; 4) The GES-induced increase in gastric volume was partially abolished by intravenous nitric oxide synthase inhibitor. GES at various sites of the stomach exerts inhibitory effect on gastric tone; the most effective sites are in the antrum along the lesser or greater curvature; the inhibitory effect of GES on gastric tone is partially mediated by the vagal and nitrergic pathway.     

Gastric hypersensitivity induced by oesophageal acid infusion in healthy volunteers

Abstract  Distal oesophageal acid exposure has been shown to increase visceral sensitivity of the proximal oesophagus via central sensitization. Here we evaluated whether acidification of the distal oesophagus also affects the sensorimotor function of the proximal stomach. A gastric barostat study combined with a 30-min acid (HCl 0.15 mol L⁻¹) or saline infusion in the distal oesophagus was performed in 18 healthy volunteers. Gastric and cutaneous sensitivity was assessed before and up to 2 h after the start of infusion. Directly after acid infusion, but not after saline, the threshold for discomfort decreased (–6.4 ± 1.7 vs 0.4 ± 0.4 mmHg; P = 0.028) and distension-induced symptoms increased significantly compared with the baseline (122 ± 49% vs −3 ± 9%). Cutaneous sensitivity remained unaffected by acid infusion. In contrast, when the infused liquid was aspirated 3 cm more distally, at the level of the lower oesophageal sphincter, the effect of acid infusion on gastric sensitivity was abolished and the increase in distension-induced symptoms was reduced (61 ± 24%). Distal oesophageal acid infusion induces visceral hypersensitivity without affecting somatic sensitivity arguing against a similar mechanism of central sensitization as observed in non-cardiac chest pain. As reduction of the acid load to the stomach prevented this effect, our findings indicate that either gastric and/or duodenal acidification is involved. It should be emphasized though that aspiration from distal oesophagus may have attenuated the effect by reducing the acid-exposed area or by reducing the contact time.     

Oesophageal afferent pathway sensitivity in non-erosive reflux disease

Abstract  Patients with non-erosive reflux disease (NERD) report symptoms which commonly fail to improve on conventional antireflux therapies. Oesophageal visceral hyperalgaesia may contribute to symptom generation in NERD and we explore this hypothesis using oesophageal evoked potentials. Fifteen endoscopically confirmed NERD patients (four female, 29–56 years) plus 15 matched healthy volunteers (four female, 23–56 years) were studied. All patients had oesophageal manometry/24-h pH monitoring and all subjects underwent evoked potential and sensory testing, using electrical stimulation of the distal oesophagus. Cumulatively, NERD patients had higher sensory thresholds and increased evoked potential latencies when compared to controls ( P  = 0.01). In NERD patients, there was a correlation between pain threshold and acid exposure as determined by DeMeester score ( r  = 0.63, P  = 0.02), with increased oesophageal sensitivity being associated with lower DeMeester score. Reflux negative patients had lower pain thresholds when compared to both reflux positive patients and controls. Evoked potentials were normal in reflux negative patients but significantly delayed in the reflux positive group ( P  = 0.01). We demonstrate that NERD patients form a continuum of oesophageal afferent sensitivity with a correlation between the degree of acid exposure and oesophageal pain thresholds. We provide objective evidence that increased oesophageal pain sensitivity in reflux negative NERD is associated with heightened afferent sensitivity as normal latency evoked potential responses could be elicited with reduced afferent input. Increased oesophageal afferent pain sensitivity may play an important role in a subset of NERD and could offer an alternate therapeutic target.     

Gastric dysreflexia after acute experimental spinal cord injury in rats

Abstract  Gastric reflexes are mediated mainly by vago-vagal reflex circuits in the caudal medulla. Despite the fact that brainstem vago-vagal circuitry remains intact after spinal cord injury (SCI), patients with SCI at the cervical level most often present gastric stasis with an increased risk of reflux and aspiration of gastric contents. Using a miniature strain gauge sutured to the gastric surface; we tested gastric motility and reflexive gastric relaxation following oesophageal distension (oesophageal-gastric relaxation reflex) in animals 3 days after a severe spinal contusion at either the third or ninth thoracic spinal segment (acute T3- or T9 SCI, respectively). Both basal gastric motility and the oesophageal-gastric relaxation reflex were significantly diminished in animals with T3 SCI. Conversely, both basal gastric motility and the oesophageal-gastric relaxation reflex were not significantly reduced in T9 SCI animals compared to controls. The reduced gastric motility and oesophageal-gastric reflex in T3 SCI rats was not ameliorated by celiac sympathectomy. Our results show that gastric stasis following acute SCI is independent of altered spinal sympathetic input to the stomach caudal to the lesion. Our data suggest that SCI may alter the sensitivity of vagal reflex function, perhaps by interrupting ascending spinosolitary input to brainstem vagal nuclei.     

Effect of oesophagitis on proximal extent of gastro-oesophageal reflux

Proximal oesophageal acid reflux is increased in gastro-oesophageal reflux disease (GORD) patients with oesophageal and extra-oesophageal symptoms, the latter particularly in presence of oesophagitis. This study was aimed to assess the proximal extent of reflux, both acid and weakly acidic, in GORD patients with and without oesophagitis and to characterize, using an animal model of GORD, the relationship between acute oesophagitis and proximal extent of reflux. Proximal extent of reflux was evaluated during 24-h pH-impedance monitoring in 17 oesophagitis, 27 non-erosive reflux disease (NERD) patients and 10 asymptomatic controls. In five adult cats, reflux events were simulated by intra-oesophageal retrograde injection of a radiopaque solution. Proximal extent of simulated reflux was fluoroscopically assessed before and after inducing acute oesophagitis. The percentage of proximal reflux was 11% in controls, 22% in NERD and 38% in oesophagitis patients (P < 0.05 vs NERD). Weakly acidic reflux showed higher proximal extent in oesophagitis than in NERD patients but it was less proximally propagated than acid reflux. In cats, proximal reflux was significantly increased during acute oesophagitis. Oesophagitis patients show higher proximal extent of reflux, acid and weakly acidic, when compared with NERD patients and controls. In the experimental model, acute oesophagitis favours proximal migration of simulated reflux.     

Postprandial gastric antral contractions in patients with gastro-oesophageal reflux disease: a scintigraphic study

Abstract  Disturbed gastric contractility has been found in manometric studies in patients with gastro-oesophageal reflux disease (GORD), but the pathophysiological role of this abnormality is unclear. We aimed at assessing postprandial gastric antral contractions and its relationships with gastric emptying and gastro-oesophageal reflux in GORD patients. Fasted GORD patients ( n  = 13) and healthy volunteers ( n  = 13) ingested a liquid meal labelled with 72 MBq of ^99mTechnetium-phytate. Gastric images were acquired every 10 min for 2 h, for measuring gastric emptying half time. Dynamic antral scintigraphy (one frame per second), performed for 4 min at 30-min intervals, allowed estimation of both mean dominant frequency and amplitude of antral contractions. In GORD patients ( n  = 10), acidic reflux episodes occurring 2 h after the ingestion of the same test meal were determined by ambulatory 24-h oesophageal pH monitoring. Gastric emptying was similar in GORD patients and controls (median; range: 82 min; 58–126 vs 80 min; 44–122 min; P  = 0.38). Frequency of antral contractions was also similar in both groups (3.1 cpm; 2.8–3.6 vs 3.2 cpm; 2.4–3.8 cpm; P  = 0.15). In GORD patients, amplitude of antral contractions was significantly higher than in controls (32.7%; 17–44% vs 23.3%; 16–43%; P  = 0.01), and correlated positively with gastric emptying time ( R _s = 0.58; P  = 0.03) and inversely with the number of reflux episodes ( R _s = −0.68; P  = 0.02). Increased amplitude of postprandial gastric antral contractions in GORD may comprise a compensatory mechanism against delayed gastric emptying and a defensive factor against acidic gastro-oesophageal reflux.     

Postprandial proximal gastric acid pocket in patients after distal gastrectomy

Background An unbuffered postprandial proximal gastric acid pocket (PPGAP) has been noticed in the majority of normal individuals and patients with gastroesophageal reflux disease. The role of gastric anatomy, specifically the antrum, in the physiology of the PPGAP is not yet fully elucidated. This study aims to analyze the presence of PPGAP in patients submitted to distal gastrectomy. Methods A total of 15 patients who had a distal gastrectomy plus DII lymphadenectomy and Roux‐en‐Y reconstruction for gastric adenocarcinoma (mean age 64.3 ± 8.4 years, 12 females) were studied. All patients were free of foregut symptoms after the operation. Patients underwent a high‐resolution manometry. A station pull‐through pH monitoring was performed from 5 cm below the lower border of the lower esophageal sphincter (LBLES) to the LBLES in increments of 1 cm in a fasting state and 10 min after a standardized fatty meal. Postprandial proximal gastric acid pocket was defined by the presence of acid reading (pH<4) in a segment of the proximal stomach between non‐acid segments distally (food) and proximally (LBLES). The PPGAP extent was recorded. The protocol was approved by local ethics committee. Key Results Acidity was not detected in the stomach of nine patients before meal. After meal, PPGAP was not found in three patients. In three patients (20%), a PPGAP was noted with an extension of 1, 1 and 3 cm. Conclusions & Inferences In conclusion, PPGAP is present in a minority of patients after distal gastrectomy; this finding may suggest that the gastric antrum may play a role in the genesis of the PPGAP.     

Impaired egress rather than increased access: an important independent predictor of erosive oesophagitis

Oesophagitis severity is related to total oesophageal acid exposure, which is in turn dependent upon both the number reflux events and the rate of refluxate clearance. This study examined differences in the frequency of reflux events and the characteristics of oesophageal acid exposure in asymptomatic controls and gastro-oesophageal reflux disease (GORD) patients both with and without oesophagitis. Nine controls and 38 patients with GORD were studied. All patients underwent upper endoscopy, videofluoroscopy, determination of resting lower oesophageal sphincter pressure (LOSP) and 24 h pH monitoring. Analysis was performed with subjects grouped as controls, non-erosive GORD and oesophagitis. A second analysis was performed with subjects grouped by hiatal hernia size. Statistical comparisons were made using anovaand unpairedt-tests. Patients with oesophagitis had significantly larger hiatal hernias, greater oesophageal acid exposure, more prolonged episodes of reflux and longer acid clearance times than did controls and patients with non-erosive GORD. No significant difference was seen in the number of reflux events. Increasing hiatal hernia size was significantly associated with increasing oesophageal acid exposure, number of prolonged reflux events and prolonged acid clearance times. Oesophagitis patients have significantly greater oesophageal acid exposure than subjects with non-erosive GORD. Increased oesophageal acid exposure in oesophagitis is attributable to impaired acid clearance and the greatest impairments in refluxate clearance occur in patients with large hiatal hernias.     

Regional gastric emptying abnormalities in functional dyspepsia and gastro-oesophageal reflux disease

To characterize proximal and distal stomach emptying in functional dyspepsia (FD) and gastro-oesophageal reflux disease (GORD). Eighty-three patients underwent gastric emptying (GE) scintigraphy and symptom scoring for the evaluation of upper gastrointestinal symptoms and were divided into three groups: FD (n = 25), GORD (n = 20) and FD + GORD (n = 38). Total, proximal and distal gastric retention were determined scintigraphically and compared with normal controls. Delayed total GE was observed in each subgroup: FD (56%), GORD (45%) and FD + GORD (55%). Greater proximal gastric retention was observed after meal ingestion in GORD compared to FD. Greater distal gastric retention was observed in FD and FD + GORD but it was only mild in GORD. Nausea, vomiting, early satiety, distention and regurgitation were associated with proximal gastric retention whereas there was no symptom associated with distal gastric retention. Multiple regression demonstrated total gastric retention at 30 min and 1 h was positively correlated with regurgitation whereas early proximal gastric retention was positively correlated with regurgitation and negatively correlated with nausea. Selective abnormalities of proximal and distal stomach emptying were demonstrated in GORD and FD. GORD and FD symptoms were associated with proximal gastric retention suggesting that proximal stomach motor function may be important in the pathogenesis of symptoms associated with these disorders.     

Elicitation of transient lower oesophageal sphincter relaxations in response to gastric distension and meal ingestion

The aim of this study was to compare the effect of graded gastric barostat distension and meal-induced fundic relaxation on the elicitation of transient lower oesophageal sphincter relaxation (TLOSR). In 15 healthy subjects, stepwise fundic distension and oesophageal manometry were performed simultaneously. Next, the effect of meal ingestion on proximal stomach volume and lower oesophageal sphincter function was studied. During stepwise barostat distension of the proximal stomach, a significant linear correlation between intragastric pressure (r = 0.91; P < 0.01) and the TLOSR rate during inflation and subsequent deflation (r = 0.96; P < 0.01) was found. A similar relationship was found for volume. In addition, after meal ingestion, the TLOSR rate increased significantly from 1.40 +/- 3 to 5.4 +/- 1.5 h-1 (P < 0.01) and 5.2 +/- 1.7 h-1 (P < 0.01), respectively, during the first and second 30-min postprandially. However, at similar calculated intragastric volumes, barostat distension led to a significantly higher TLOSR rate than the meal. Similarly, distension-induced increase in gastric wall tension, estimated from the measured bag pressure and volume using Laplace's law, was associated with significantly higher TLOSR rates (P < 0.01). In conclusion, the rate of TLOSRs in healthy volunteers is directly related to the degree of proximal gastric distension and pressure-controlled barostat distension is a more potent trigger of TLOSRs than a meal. The latter finding suggests that tension receptor activation is an important stimulus for TLOSRs.     

Postcibal secretory and symptomatic responses to increased intragastric pressure

Abstract The mechanical and secretory factors in the stomach that may be implicated in the production of symptoms are still poorly understood. To determine whether symptoms in response to postcibal gastric distention are associated with increased acid secretion, the relationship between symptoms, acid secretion and intragastric pressure in healthy subjects was investigated. Perception (by a 0–6 score questionnaire) and the gastric secretory response to a glucose test meal (by intragastric titration) was quantified either at low (2 mmHg) or at high (8 mmHg) intragastric pressure levels, maintained by feedback regulation of the air volume within a gastric bag using an electronic barostat. Low intragastric pressure produced a small gastric expansion (87 ± 26 ml; mean ± SE) that was largely unperceived (score 0.7 ± 0.5). High intragastric pressure did not increase acid secretion (15 ± 3 mEq h^-1 vs 16 ± 3 mEq h^-1 at low pressure), but produced symptomatic perception (score 2.5 ± 0.7) related to a marked gastric expansion (521 ± 92 ml; P < 0.05 vs low pressure for both). It was concluded that postcibal gastric hypertension induces symptoms without affecting the gastric acid secretory response to the meal.     

Postprandial proximal gastric acid pocket and gastric pressure in patients after gastric surgery

Background An unbuffered postprandial proximal gastric acid pocket (PPGAP) has been demonstrated in normal individuals (NI) and patients with gastro‐esophageal reflux disease (GERD). The role of gastric anatomy and gastric motility in the physiology of the PPGAP remains elusive. This study aims to analyze the correlation of PPGAP with proximal gastric pressure after gastric surgery. Methods A total of 26 individuals were studied: eight patients after open Roux‐en‐Y gastric bypass (RYGB) for morbid obesity, six patients after laparoscopic Nissen fundoplication for GERD, seven patients after open subtotal gastrectomy for gastric cancer and five NI. Patients underwent high resolution manometry to identify the location of the lower border of the lower esophageal sphincter (LBLES) and measure gastric pressure 1, 2, 3, 4 and 5 cm below the LBLES, immediately before swallow and after the end of the LES relaxation. A station pull‐through pH monitoring was performed in all but NI, from 5 cm below the LBLES to the LBLES in increments of 1 cm in a fasting state and 10 min after a standardized fatty meal. Key Results Our results show that: (i) proximal gastric pressures are lower after swallow compared with before swallow in NI; (ii) patients after gastric surgery tend to have higher gastric pressure before and lower after swallow compared with NI and (iii) patients after RYGB with PPGAP have an increased gastric pressure after swallows in the segment where the PPGAP is noticed. Conclusions & Inferences Gastric motility may play a role in the genesis of PPGAP in patients after RYGB. The contribution of gastric motility for the genesis of PPGAP is still elusive in other patients.     

Capsaicin-Sensitive Vagal Afferent Fibers and Gastric Motility: Evidence for an "Axon Reflex" Mechanism

The role of capsaicin-sensitive afferent fibers in gastric motility has been studied in normal rats and in rats treated at birth with the sensory neurotoxin capsaicin, a procedure known to destroy up to 90% of unmyelinated afferent fibers. Gastric motility was measured as intragastric pressure changes evoked by the distention of the stomach with 8 to 10 ml of normal (154 mM) or 1 M saline solution. No differences were observed between the motility patterns evoked by gastric distention with these two solutions. Distention of the stomach evoked a significantly lower basal tone and a reduced number and amplitude of phasic contractions in capsaicin-treated rats compared to control rats. Intravenous administration of the ganglionic blocker hexamethonium substantially reduced phasic motility in both groups of animals. Subsequent bilateral vagotomy had little extra effect. After bilateral vagotomy, electrical stimulation at supramaximal intensities of the peripheral end of the cut right vagus in the presence of hexamethonium produced an inhibition of the gastric basal tone in both groups of rats and, on cessation of stimulation, a series of rebound contractions in most control animals, but not in those treated at birth with capsaicin. These results provide evidence for an efferent role of vagal afferent fibers in the control of gastric motility, possibly via an axon reflex mechanism.     

An experimental model for the study of transient lower oesophageal sphincter relaxation and motor function of the proximal stomach in humans

A simple and reliable experimental model would be useful in human research on new drugs which target transient lower oesophageal sphincter (LOS) relaxation. The aim was to investigate the effect of repeated distensions on the rate of transient LOS relaxation, LOS pressure and motor function of the proximal stomach. Twelve healthy subjects were studied with a multilumen manometric assembly incorporating a sleeve sensor for the LOS and a bag positioned in the proximal stomach and connected to a barostat. Intrabag volume was set at 75% of the threshold for gastric discomfort and maintained for two 30-min distension periods separated by a 45-min washout with the bag deflated. The studies lasted 145 +/- 2 min. The rate of transient LOS relaxations was similar during the two distensions, 3.5;2-4 vs 3;2.5-4 (median;interquartile range) and so was LOS pressure. Baseline intrabag pressure, as a measure of gastric tone, and the number of pressure waves, as a measure of phasic contractions, were also similar, 11.3;9.3-12.3 mmHg vs 10.8;9.3-12.5 mmHg and 16;13-28 mmHg vs 19;15-29 mmHg, respectively. Our model allows to perform 1-day studies which can assess two experimental conditions on transient LOS relaxations and motor function of the proximal stomach within an acceptable time span.     

A disturbance of gastric function in bulimia nervosa.

BACKGROUND: Because the stomach plays an important role in the development of satiety, gastric function was examined in bulimia nervosa (BN). METHODS: Sixteen patients with BN and 16 controls swallowed an inflatable bag, which was positioned in the proximal stomach. Minimal distending pressure (MDP), the pressure needed to overcome intraabdominal pressure, was determined. Gastric volume was recorded after subjects drank a liquid meal. RESULTS: MDP was similar in patient and control groups (7.56 +/- 2.13 vs. 7.13 +/- 2.06 mmHg; t =.57, df = 30, p =.58). Average postmeal gastric relaxation was significantly lower in the patient group (29.7 +/- 97.8 vs. 105.1 +/- 103.3 mL; t = 2.13, df = 30, p =.042). CONCLUSIONS: Stomach relaxation following food consumption is significantly diminished in patients with BN. Physiologic abnormalities of stomach function in BN may contribute to the perpetuation of disturbances in behavior in this disorder.     

Swallows, oesophageal and gastric motility in normal subjects and in patients with gastro-oesophageal reflux disease: a 24-h pH-manometric study

Background: the motor aspects underlying gastro-oesophageal reflux disease (GORD) are still not completely clear. Aim: to evaluate the relationship between oesophageal and gastric motility in GORD patients. Patients: twelve patients with grade I–II oesophagitis, mean age 45 yr, and 10 healthy subjects, mean age 42 yr, were studied. Methods: a pH-manometry was performed to analyse oesophageal and gastric motility, swallows and oesophageal pH values for the whole 24-h period, and for the 2-min period before and after each reflux episode. Results: as compared to controls, GORD patients showed in the 24-h period, a greater number of swallows (P < 0.01) and a lower percentage of post deglutitive propagated oesophageal body waves (P < 0.05). The number of migrating motor complexes (MMC) was similar in the two groups, with a lower amplitude of phase III gastric waves in GORD. During MMC reflux episodes were seen only in GORD patients. After refluxes an increase in swallows, simultaneous and secondary oesophageal waves were detected in GORD patients, with a reduction of primary peristalsis. Isolated gastric contractions preceded reflux episodes more frequently in GORD patients than in controls. Conclusions: GORD patients showed an increase in swallows with altered post-deglutitive oesophageal motility and a reduced amplitude of gastric MMC. Moreover small contractions of gastric antrum are present before acid refluxes, suggesting a multifactorial pathogenesis of the disease.     

Visceral perceptions and gastric myoelectrical activity in healthy women and in patients with bulimia nervosa

Bulimia nervosa remains a common eating disorder in young women. Little is known about upper gastrointestinal symptoms or gastric motility in patients with bulimia nervosa. The aim of this study was to measure gastric myoelectrical activity and hunger/satiety and stomach emptiness/fullness before and after a non-nutrient water load and solid-phase gastric emptying in hospitalized patients with bulimia nervosa (n = 12) and in healthy women (n = 13). Gastric myoelectrical activity was measured by means of cutaneous electrodes; visual analogue scales were used to measure perceptions of hunger/satiety and stomach emptiness/fullness. Before and after a standard water load the bulimia patients reported significantly greater stomach fullness and satiety compared with control subjects (P < 0.01). The percentage of gastric myoelectrical power in the normal 3 cpm range was significantly less in bulimics compared with controls. Power in the 1–2 cpm bradygastria range was significantly greater in bulimia patients before and after the water load compared with the control subjects (P < 0.05). Solid-phase gastric emptying studies using radio-isotope-labelled scrambled eggs showed the lag phase was shortened in the bulimic patients (16 ± 4 min vs 31 ± 4 min in controls, P < 0.01), but the percentage of meal emptied at 2 h was similar to control values. In conclusion: bulimia patients had exaggerated perceptions of stomach fullness and satiety in response to water; and abnormal gastric myoelectrical activity and accelerated lag phase of gastric emptying were objective stomach abnormalities detected in hospitalized patients with bulimia nervosa.