Peter R. Evans

Gastroparesis and Small Bowel Dysmotility in Irritable Bowel Syndrome

Alterations in both gastric emptying (GE) andsmall bowel motility have been reported in irritablebowel syndrome (IBS); the relationship, however, betweenthese different measures of upper gut motor function in IBS has not been assessed. The aims of thisstudy were therefore: (1) to compare the prevalence andcharacteristics of altered small bowel motility in IBSpatients with and without delayed GE; and (2) to assess the interrelationships betweenfasting and postprandial small bowel motility in IBS,accounting for delayed GE. Forty-four IBS patients and25 healthy controls underwent 24 hr ambulant recording of interdigestive and digestive small bowelmotility. On a separate occasion the IBS patients had GEof both solids and liquids measured by a dual-isotopescintigraphic technique. Thirty-nine percent of IBS patients had delayed GE. Patients withnormal GE had no interdigestive small bowelabnormalities. However, in patients with delayed GEfasting phase II burst frequency was higher than incontrols [median 0.21/hr (IQR 0.15–0.34) vs 0.06/hr(0–0,16), P = 0.004]. Postprandially, abnormalphase III-like activity was higher indiarrhea-predominant IBS patients (0–0.08/hr vs0/hr, P = 0.01), than in patients with normal GE or controls. Furthermore, IBSpatients with delayed GE did not have the normalcorrelation between fasting and postprandial motorparameters (percentage occurrence of clusteredcontractions, postprandial pattern duration vs preceding MMC cyclelength). In conclusion, small bowel motor dysfunctionoccurs more frequently in IBS patients with concomitantgastroparesis than in patients with normal GE. These findings provide further evidence that aneuropathic process may contribute to the pathogenesisof IBS in a subgroup of IBS patients.

Fructose-sorbitol malabsorption and symptom provocation in irritable bowel syndrome: relationship to enteric hypersensitivity and dysmotility.

BACKGROUND Fructose-sorbitol (F-S) mixtures can provoke symptoms in irritable bowel syndrome (IBS) patients, and a proportion of IBS patients also have enteric hypersensitivity to distension. We hypothesized, therefore, that sugar malabsorption and fermentation to produce hydrogen gas may provoke symptoms to a greater extent in IBS patients hypersensitive to distension than in those patients without such hypersensitivity. Our aims were therefore to compare, in IBS patients, symptoms and breath hydrogen responses after F-S, on the basis of jejunal sensitivity and jejunal motor function. METHODS Fifteen female IBS patients (44 +/- 15 years) underwent, on separate occasions, 3-h breath hydrogen analyses after ingesting 10 g lactulose and 25 g fructose with 5 g sorbitol. Jejunal sensitivity and motor function were determined by balloon distension and 24-h manometry studies, respectively. Cumulative symptom scores and breath hydrogen production were analysed on the basis of the presence or absence of jejunal hypersensitivity and dysmotility. RESULTS Four and seven patients had jejunal hypersensitivity for initial perception and pain, respectively. Eleven, nine, and nine patients had jejunal dysmotility for fasting phase 3, phase 2, and fed motor activity, respectively. Of the patients with symptom provocation after F-S (n = 8 within 3 h, n = 12 within 12 h) or with F-S malabsorption (n = 10), the relative proportion did not differ on the basis of the presence or absence of jejunal hypersensitivity or of motor dysfunction. Symptom scores and hydrogen production also were not different in these subgroups. CONCLUSIONS Although carbohydrate malabsorption can provoke symptoms in some IBS patients, there is no consistent association between such a phenomenon and the presence of either jejunal hypersensitivity or dysmotility.

Small bowel dysmotility in patients with postcholecystectomy sphincter of Oddi dysfunction

Postcholecystectomy patients (N = 27) withsevere recurrent biliary-like pain who had no evidenceof organic disease were subdivided into those with andthose without objective evidence of sphincter of Oddi dysfunction (SOD) based on two separatecriteria: (1) clinical criteria — elevated liverfunction tests and/or amylase with pain, and/or adilated bile duct, and/or delayed drainage at ERCP (N =14, SOD classes I and II); and (2) abnormal biliary manometry(N = 19). Prolonged (24–48 hr) ambulant recordingof duodenojejunal motor activity was performed in allpatients and interdigestive small bowel motor activity compared between patient subgroups and ahealthy control group. Phase II motor abnormality wasmore frequent in patients with, compared to thosewithout, objective clinical criteria of SOD (7/14 vs0/13, P = 0.003). Phase III abnormality also tendedto be more frequent in these patients (7/14 vs 2/13, P= 0.06). In addition, both phase III (P = 0.03) andphase II (P = 0.03) motility index (MI) was higher inpatients with sphincter dyskinesia compared to controls;phase II MI was also higher in patients with sphincterstenosis (P = 0.005). Disturbances of small bowelinterdigestive motor activity are more prevalent in postcholecystectomy patients with, compared tothose without, objective evidence of SOD, and especiallyin patients with SO dyskinesia. Postcholecystectomy SODin some patients may thus represent a component of a more generalized intestinal motordisorder.

Abnormal sphincter of Oddi response to cholecystokinin in postcholecystectomy syndrome patients with irritable bowel syndrome : the irritable sphincter

Standard biliary manometry, including cholecystokinin (CCK) provocation, was performed on 42 consecutive patients (36 F, 6 M, median age 45 years) with postcholecystectomy syndrome (PCS) who had no evidence of organic disease but who had objective clinical features suggesting sphincter of Oddi dysfunction (SOD) (classes I and II). Patients were subdivided into those with (N=14) and without (N=28) irritable bowel syndrome (IBS) using a validated symptom questionnaire based on the modified Rome criteria. Resting sphincter of Oddi (SO) motor parameters (basal pressure, contractile amplitude and frequency, and proportion of retrograde contractions), the presence of abnormal manometry, and the presence of an abnormal response to CCK were compared in the two groups. No significant differences in resting parameters of SO motor activity between patients with and without IBS were observed, and abnormal biliary manometry as a whole was not more prevalent in either group (8/13 and 18/27, respectively). An abnormal response to CCK (failure of complete inhibition of phasic contractions), however, was demonstrated in five of 12 patients with IBS compared with only one of 23 patients without IBS (P=0.01). In patients with postcholecystectomy SOD, an abnormal response of the SO to CCK thus appears to be an important feature of the subset of patients with concomitant IBS.

Psychological and sex features of delayed gut transit in functional gastrointestinal disorders

BACKGROUND The relation of demographic and psychological factors to the presence and extent of gut transit impairment in the functional gastrointestinal disorders has received little attention. AIMS To compare the psychosocial and demographic features of patients with functional gastrointestinal disorders and delayed transit in one region of the gastrointestinal tract with those displaying more widespread delayed transit (that is, delay in two or three regions), and those with normal transit in all three regions. PATIENTS Of 110 outpatient participants who satisfied standardised criteria for functional gastrointestinal disorders, 46 had delayed transit in one region, 32 had delay in two or three regions, and 17 exhibited normal transit in all regions. METHODS Transit in the stomach, the small intestine, and the large intestine was assessed concurrently using a wholly scintigraphic technique; psychological status was assessed using established psychometric measures. RESULTS Patients with delayed transit displayed demographic and psychological features that contrasted with patients with normal transit in all regions. In particular, widespread delayed transit featured female sex, a highly depressed mood state, increased age, frequent control of anger, and more severe gastric stasis, while the features distinguishing normal transit were male sex and high levels of hypochondriasis. CONCLUSION These data suggest the existence of a distinct psychophysiological subgroup, defined by the presence of delayed transit, in patients with functional gastrointestinal disorders.

Physiological modulation of jejunal sensitivity in health and in irritable bowel syndrome

Objectives:In irritable bowel syndrome (IBS), enhanced sensitivity to distention of the small bowel has been demonstrated. We sought to compare, in healthy subjects and in IBS patients, the effects on jejunal sensitivity and compliance of feeding, nonperceived rectal mechanoreceptor stimulation, and the above two stimuli in combination.Methods:Eleven female IBS patients (49 ± 13 yr)—six with predominant constipation (IBS-C), and five with predominant diarrhea (IBS-D)—and seven healthy female controls (39 ± 13 yr) participated. Jejunal distention was applied during fasting, 30 min after a 400-kcal meal, and also during simultaneous nonperceived rectal stimulation.Results:Jejunal sensitivity was increased after feeding in IBS patients (p= 0.004), specifically in IBS-C patients (p= 0.0001) and in controls (p= 0.02), and was reduced during rectal stimulation in IBS patients (p= 0.0001)—both in IBS-D (p= 0.0001) and in IBS-C (p= 0.03) patients—but not significantly so in controls (p= 0.06). Jejunal sensitivity remained unaltered in both IBS patients and controls during concurrent feeding and rectal stimulation.Conclusions:Physiological stimuli in different parts of the gut modify the intensity of jejunal perception, and the interaction of such stimuli further modifies enteric sensitivity. Nonperceived rectal stimulation appears to modify the intensity of jejunal perception to a greater extent in IBS than in health.

Alterations in cerebral potentials evoked by rectal distension in irritable bowel syndrome

OBJECTIVE:Central nervous system correlates of the visceral hyperalgesia documented in patients with irritable bowel syndrome are limited. Reproducible cerebral evoked potentials can be recorded in response to rhythmic balloon distension of the rectum in healthy adults. Irritable bowel syndrome patients and healthy subjects were studied to compare the characteristics of mechanically-evoked rectal cerebral potentials obtained during fasting and after the ingestion of a standard meal.METHODS:Twenty-two pairs of age-matched healthy female subjects and female irritable bowel syndrome patients were studied. Cerebral evoked potentials were recorded in response to rhythmic rectal distension (two distension series each of 100 repetitions at 0.8 hertz); cerebral evoked potential recordings were repeated after a 1000 kcal (46% fat) liquid meal. Trait and state anxiety questionnaires were also completed.RESULTS:Compared to healthy subjects, irritable bowel syndrome patients demonstrated higher prevalence of cerebral evoked potential early peaks (latency < 100 ms) postprandially, and uniformly shorter cerebral evoked potential latencies both before and after feeding.CONCLUSION:These findings provide further objective evidence for defective visceral afferent transmission in irritable bowel syndrome patients.

Discordance of pressure recordings from biliary and pancreatic duct segments in patients with suspected sphincter of Oddi dysfunction.

It remains controversial whether manometricparameters recorded from the pancreatic and biliarysegment of the sphincter of Oddi (SO) differ. Wetherefore studied 48 consecutive patients (40 women, 4311 years) with suspected SO dysfunction, in 33 ofwhom successful dual-duct SO manometry was obtained.Measures of concordance between the two duct segmentswere moderate for basal sphincter pressure (K = 0.31) and for contractile frequency (0.35), and werelow for peak pressure (0.15) and for proportion ofretrograde propagation (–0.19). There was also lowconcordance (–0.13) for the overall manometricdiagnosis, and in 48% (CI 31-66%) of patients aconflicting diagnosis (normal/abnormal) was obtainedfrom the two ducts. There was no evidence of adifferential motor effect of CCK on either duct, norwere there significant differences in the rate of manometricabnormality according to the order of initial ductcannulation. These results indicate that, if technicallyfeasible, dual-duct manometry of the sphincter of Oddiis required for diagnostic precision.

Mebeverine alters small bowel motility in irritable bowel syndrome

Background and Aim: Despite its widespread use in irritable bowel syndrome (IBS), limited clinical data exist on the effects of mebeverine hydrochloride on gastrointestinal motility. Human motor activity in the small bowel is more reproducible than that in the large bowel; therefore the aim of this study was to determine in the small bowel the effects of oral mebeverine in both IBS patients and in healthy controls.

Effects of oral cisapride on small bowel motility in irritable bowel syndrome

Cisapride has been reported to improve symptoms in patients with constipation‐predominant irritable bowel syndrome.