Intraduodenal lipid infusion induces symptoms and increases sensitivity to gastric distension in patients with functional dyspepsia. To test whether these effects are specific for lipid, we compared the effects of intraduodenal infusions of either lipid or glucose on symptoms and gastric sensory and motor responses to gastric distension. Eighteen dyspeptic patients and nine controls were studied. The stomach was distended with a flaccid bag during isocaloric infusions (1 kcal/ml) of saline and either 10% Intralipid (nine patients) or 26.7% glucose (nine patients) into the duodenum. Dyspeptic symptoms and sensory thresholds for epigastric fullness and discomfort were assessed. Gastric pressure profiles during distensions were similar during lipid and glucose infusions in patients and controls, but both were significantly lower than during saline infusion. Lower volumes were required to induce fullness and discomfort in the patients compared with the controls. In the controls, the threshold volumes required to induce fullness and discomfort were greater during infusion of lipid and glucose than during saline infusion, but in the patients, the threshold volumes were increased during glucose infusion but further reduced during lipid infusion. Moreover, in the patients, nausea was more common during lipid than glucose infusion and did not occur during saline. The controls did not experience any symptoms during any infusion. In conclusion, intraduodenal lipid but not glucose sensitizes the stomach to distension in patients with functional dyspepsia but not in controls.

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We studied 14 unselected patients with progressive systemic sclerosis (PSS), six with constipation, and eight with normal bowel habits. A control group, matched for age and sex, comprised six patients with idiopathic constipation and seven healthy subjects. Anorectal manometry was performed with perfused catheters and segmental colonic transit was measured by a radiopaque marker technique. The resting pressure of the anal canal was significantly reduced in PSS with constipation (P < 0.05). The rectoanal inhibitory reflex was detected in only one PSS patient with constipation, but was present in seven of eight PSS patients with normal bowel habits and in all controls (P < 0.01). Total and right colonic transit times were significantly delayed in PSS with constipation and in patients with idiopathic constipation (P < 0.05). In patients with PSS, colonic transit was delayed and anal sphincter function was impaired in constipated patients, suggesting involvement of both the colon and the anorectum by the disease.

Background-The relative roles of gastric relaxation and the neuroendocrine signals released by the small intestine in the perception of nutrient induced sensations are controversial. The diVerent eVects of long chain (LCT) and medium chain (MCT) triglyceride ingestion on perception, gastric relaxation, and hormonal release may help to elucidate the mechanisms underlying nutrient induced sensations. Aims-To compare the eVects of intraduodenal LCT and MCT infusions on perception, gastric tone, and plasma gut hormone levels in healthy subjects. Subjects-Nine fasting healthy volunteers. Methods-The subjects received duodenal infusions of saline followed by LCTs and MCTs in a randomised order on two diVerent days. The sensations were rated on a visual analogue scale. Gastric tone was measured using a barostat, and plasma gut hormone levels by radioimmunoassay. Results-LCT infusion increased satiation scores, reduced gastric tone, and increased the levels of plasma cholecystokinin, gastric inhibitory polypeptide, neurotensin, and pancreatic polypeptide. MCT infusion reduced gastric tone but did not significantly aVect perception or plasma gut hormone levels. LCTs produced greater gastric relaxation than MCTs. Conclusions-The satiation induced by intraduodenal LCT infusion seems to involve changes in gastric tone and plasma gut hormone levels. The gastric relaxation induced by MCT infusion, together with the absence of any significant change in satiation scores and plasma hormone levels, suggests that, at least up to a certain level, gastric relaxation is not suYcient to induce satiation and that nutrient induced gastric relaxation may occur through cholecystokinin independent mechanisms. (Gut 2000;46:32-36) Keywords: gastric tone; triglyceride; hormones; satiation; cholecystokinin; nutrients The relative roles of gastric relaxation and the neuroendocrine signals released by the small intestine in the perception of the sensations induced by nutrients are still unclear. Changes in the chemical composition of nutrients infused into the duodenum lead to diVerent sensations despite a similar increase in gastric distensibility, which suggests that the neuroendocrine signals released by the small intestine influence nutrient induced sensations.