Central control of human gastrointestinal function

Antroduodenal manometry. Usefulness and limitations as an outpatient study

We performed fasting and postprandial recordings of antroduodenal manometry in 21 normal volunteers, 13 patients with insulin-dependent diabetes mellitus and gastrointestinal symptoms, and 11 patients with the irritable bowel syndrome. None of the patients or volunteers had previously undergone an intestinal intubation study. Recordings could not be obtained from four of the diabetic patients due to failure to intubate the pylorus. Catheter migration led to incomplete antral data in a further 21% of all recordings. Due to the wide variations demonstrated by the normal volunteers, parameters of either the migrating motor complex (MMC) or the fed response could not differentiate between either of the patient groups and/or the controls. Similarly, while abnormal patterns of either fasting or postprandial motility were common in the diabetic patients, manometry had a sensitivity of only 67% in comparison to the less invasive radionuclide gastric emptying study. Furthermore, manometry failed to identify any diagnostic abnormality in irritable bowel patients; in particular, the incidence of "clustered" contractions was similar in all three groups. We conclude that short duration antroduodenal manometry is of limited diagnostic usefulness due to the difficulties in pyloric intubation in the presence of a dilated stomach and the intrinsic variability in normal motor patterns, perhaps excerbated by the stressful effects of the procedure itself in tube-naive subjects.

Experimental ischaemic tourniquet pain delays gastric emptying of semi-solids in healthy volunteers

The effect of controlled, experimental ischaemic pain, induced by tourniquet, on gastric emptying of a semi-solid meal of Tc-99m labelled Chelex-100 resin oatmeal was assessed in seven healthy volunteers, each acting as his/her own control. In the pain study, the submaximal effort tourniquet test was applied immediately, 30 min and 45 min after beginning of the study. Pain intensity was rated during the procedure using a linear visual analogue scale (VAS). All subjects participating in the study assessed their pain as close to maximal tolerance after 2-4 min. The pain stimulus caused an immediate acceleration, followed by a reproducible, significant delay in gastric emptying relative to the control situation. The median reduction in meal emptied after 60 min in the pain study was 15% P = 0.035). There was no difference in the duration of the lag period between the groups.

Life stress and non-ulcer dyspepsia: a case-control study

Sixty-two patients with persistent NUD symptoms were compared with healthy persons of comparable age, sex and social status on a variety of life stress, personality, mood state and coping measures. Highly threatening chronic difficulties were significantly more evident in the NUD group than controls (98 and 2% respectively), as were acute life events which remained highly threatening one week after their onset. Other psychological variables significantly related to NUD were high levels of anxiety and depressive symptoms, personality traits indicating neurotic or anxious tendencies, a tendency to use less mature stress-coping mechanisms and to have less high-quality emotional support. Multivariate analysis revealed the presence of highly threatening stressors to be by far the most important predictor of NUD status. The implications of these findings in relation to the significance of stress and other psychological variables in the aetiology and treatment of NUD are discussed.

The effect of phentolamine on basal and pethidine-induced inhibition of gastric emptying in healthy volunteers

1. The effect of phentolamine 5 mg i.v. on basal and pethidine-induced inhibition of gastric emptying of semisolid TC-99m labelled Chelex-100 resin/oatmeal was studied in ten healthy volunteers. 2. Each volunteer acted as his/her own control. 3. Basal gastric emptying remained unchanged after administration of phentolamine. 4. Administration of phentolamine reversed the pethidine-induced inhibition of gastric emptying.