R. Penagini

Transient lower esophageal sphincter relaxation

RAVINDER K. MITTAL,* RICHARD H. HOLLOWAY,* ROBERTO PENAGINI, § L. ASHLEY BLACKSHAW, t and JOHN DENT* *Department of Internal Medicine, University of Virginia, Charlottesville, Virginia; *Gastrointestinal Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia; and §Cattedra di Gastroenterologia, Istituto di Scienze Mediche, University of Milan, IRCCS Ospedale Maggiore, Milan, Italy

Motor events underlying gastro‐oesophageal reflux in ambulant patients with reflux oesophagitis

Abstract Information on the mechanism of gastro‐oesophageal reflux in patients with reflux disease is limited largely to studies in resting recumbent subjects. Evidence exists that both posture and physical activity may influence reflux. The aim of this study was to investigate reflux mechanisms in ambulant patients with reflux oesophagitis.

Motor function of the proximal stomach and visceral perception in gastro-oesophageal reflux disease

Background—The abnormally high postprandial rate of transient lower oesophageal sphincter relaxations seen in patients with reflux disease may be related to altered proximal gastric motor function. Heightened visceral sensitivity may also contribute to reporting of symptoms in these patients. Aims—To assess motor function of the proximal stomach and visceral perception in reflux disease with a barostat. Methods—Fasting and postprandial proximal gastric motility, sensation, and symptoms were measured in nine patients with reflux disease and nine healthy subjects. Gastric emptying of solids and liquids was assessed in six of the patients on a different day (and compared to historical controls). Results—Minimal distending pressure and gastric compliance were similar in the two groups, whereas the patients experienced fullness at lower pressures (p<0.05) and discomfort at lower balloon volumes (p<0.005) during isobaric and isovolumetric distensions respectively. Maximal gastric relaxation induced by the meal was similar in the two groups. Late after the meal, however, proximal gastric tone was lower (p<0.01) and the score for fullness higher (p<0.01) in the reflux patients, in whom the retention of both solids and liquids in the proximal stomach was greater (p<0.05). Conclusions—Reflux disease is associated with delayed recovery of proximal gastric tone after a meal and increased visceral sensitivity. The former may contribute to the increased prevalence of reflux during transient lower oesophageal sphincter relaxations and the delay in emptying from the proximal stomach, whereas both may contribute to symptom reporting.

Effect of increasing the fat content but not the energy load of a meal on gastro-oesophageal reflux and lower oesophageal sphincter motor function

Background—Although fatty foods are commonly considered detrimental in patients with reflux disease, no objective data exist that substantiate this belief. Aims—To investigate the effect of fat on gastro-oesophageal reflux and lower oesophageal sphincter (LOS) motor activity. Subjects—Thirteen healthy subjects and 14 patients with reflux disease. Methods—Oesophageal pH, LOS, and oesophageal pressures were recorded for 180 minutes after a high fat (52% fat) and a balanced (24% fat) meal (both 3.18 MJ) on two different occasions. Eight controls and seven patients were studied in the recumbent position and the others in the sitting position. Results—The percentage of time at pH less than 4 and the rate of reflux episodes were higher (p<0.01) in the patients than in the healthy subjects (mean 14.1% versus 1.7% and 4.4/h versus 0.8/h respectively), as was the percentage of transient LOS relaxations associated with reflux (62% versus 32%, p<0.01). The high fat meal did not increase the rate of reflux episodes nor exposure to oesophageal acid in either group regardless of body posture.The rate of transient LOS relaxations, their association with reflux, and basal LOS pressure were also unaffected. Conclusions—Increasing fat intake does not affect gastro-oesophageal reflux or oesophagogastric competence for at least three hours after a meal.

Multiple rapid swallowing: a complementary test during standard oesophageal manometry

Abstract  Multiple rapid swallowing (MRS) stimulates neural inhibition resulting in abolition of contractions in the oesophageal body (OB) and complete lower oesophageal sphincter (LOS) relaxation which is followed by peristalsis and LOS contraction. The aim of this study was to evaluate the yield of MRS to detect abnormalities in inhibitory or excitatory oesophageal mechanisms in patients with oesophageal symptoms and either normal standard manometry or ineffective oesophageal motility (IOM). MRS (five water swallows, 2 mL, separated by 2–3 s) was evaluated in 23 healthy subjects, 109 symptomatic patients with normal standard sleeve manometry and in 48 patients with IOM. Healthy subjects had complete inhibition of OB motility during MRS and a strong motor response after MRS, i.e. amplitude of OB contractions in the oesophageal body and LOS tone being higher than after single swallows. Almost 70% of patients with oesophageal symptoms and normal manometry had abnormal MRS, mainly consistent on inability to increase amplitude of OB contractions after MRS. Nearly, half of the patients with IOM were able to normalize OB contractions after MRS. MRS is a simple complementary test that can be added to standard oesophageal manometry. Two‐thirds of patients with normal manometry show abnormal MRS that could potentially underlie their symptoms. A normal response to MRS in patients with severe IOM might be used to predict response to prokinetic treatment.

Effect of loperamide and naloxone on mouth-to-caecum transit time evaluated by lactulose hydrogen breath test.

The effect of loperamide and naloxone on mouth-to-caecum transit time was evaluated by the lactulose hydrogen breath test in four men and four women. Each subject underwent tests during the administration of placebo, loperamide (12-16 mg po), naloxone (40 micrograms/kg/h by a three-hour intravenous infusion), and loperamide plus naloxone, carried out at intervals of one or two weeks. The transit time was significantly longer after loperamide, and this effect was antagonised by the concomitant administration of naloxone whereas naloxone administered alone had no effect on mean transit time. No clinically important side effects were reported.

Bile reflux and oesophagitis.

• Duodenal contents, and especially bile acids and trypsin, are noxious to the oesophageal mucosa, their damaging potential depending on pH.• Various methodologies have been used to measure duodenogastric or duodenogastro-oesophageal reflux, all of them having technical limitations.• Controversy exists as to the extent of duodenogastric reflux in GORD.• Reflux of both acid and duodenal contents into the oesophagus increases with worsening of oesophagitis. Experimental data suggest that bile acids and trypsin are noxious to the oesophageal mucosa and that their damaging potential depends on pH. The injurious concentrations are, however, higher than those usually observed in the human oesophagus. Direct measurement of bile acids and trypsin is difficult and various methodologies have been used to measure duodenogastric or duodenogastro-oesophageal reflux, all of them having technical limitations. Whereas available data as to the extent of duodenogastric reflux in gastro-oesophageal reflux disease (GORD) are controversial, most observations show that reflux of both acid and duodenal contents into the oesophagus increases with worsening of oesophagitis. Furthermore, acid and duodenal contents occur simultaneously in most reflux episodes. In this issue of the journal, Marshall et al. report that exposure of the gastric fundus to duodenal contents as assessed by bilirubin monitoring is similar in GORD patients with varying degrees of oesophageal mucosal injury and in healthy controls.

Effect of Calories and Fat on Postprandial Gastro-oesophageal Reflux

Background: Gastro-oesophageal reflux (GOR) is commonly considered to be worsened by fatty food, but it has recently been shown that changing the fat content of equicaloric meals has no effect on GOR over a 3-h postprandial period. Our aims were to verify this finding over a longer postprandial period and test the hypothesis that increasing the caloric content of balanced meals increases GOR. Methods: Thirteen healthy subjects (6 men) aged 19-31 years underwent 6-h oesophageal pH monitoring after 3 solid/liquid meals of the same volume and osmolarity eaten on separate days in a randomized order: a) high fat (58% fat) 2.8 MJ; b) balanced (23% fat) 2.8 MJ; and c) balanced low calorie (25% fat) 1.6 MJ. Results: The mean percentage of time at pH < 4 and the mean number of reflux episodes after the balanced 2.8 MJ meal (3.0% and 11.5, respectively) were higher ( P < 0.05) than after the balanced 1.6 MJ meal (1.6% and 7.2) and similar to those after the equicaloric (2.8 MJ) high-fat meal (2.5% and 9.3). Acid clearance time was similar after all three meals. Conclusions: Our data suggest that advice on dietary habits in patients with GOR disease should be concentrated on decreasing the caloric load of meals rather than their fat content.

A pneumatic dilation strategy in achalasia: prospective outcome and effects on oesophageal motor function in the long term

Aliment Pharmacol Ther 31, 658–665

Lactose malabsorption and intolerance in Italians: clinical implications

Lactose malabsorption was assessed by the hydrogen breath test in 40 Italian patients with irritable bowel syndrome and 42 controls without abdominal disturbances. Sixty-five percent of patients were “low milk consumers” (0–250 ml milk per day) compared with 38% of controls (P<0.02). Lactose loads of 25 and 50 g caused malabsorption in 82.5 and 87.5% patients and in 55 and 62% controls, respectively (patients vs controlsP<0.02). Malabsorption was more frequent in the “low milk consumers” group (P<0.05). During a four-month lactose-free diet as the only treatment 7.5% of patients became symptomfree (and remained so for a further eight-month diet), 52.5% improved, and 40% showed no change.