Effect of extrinsic denervation on muscarinic neurotransmission in the canine ileocolonic region

To explore the hypothesis that denervation hypersensitivity increases ileocolonic motor activity after extrinsic denervation, we compared muscarinic neurotransmission in canine ileocolonic loops that were isolated and either extrinsically innervated or extrinsically denervated. We recorded ileal, ileocolonic sphincter (ICS) and colonic pressures, and colonic tone, compliance and relaxation during ileal distention. Muscarinic effects were probed by neostigmine, and minimally effective doses of muscarinic receptor antagonists. Denervation augmented ileal, ICS and colonic contractile activity; colonic high-amplitude propagating contractions (HAPCs) were also augmented; colonic relaxation during ileal distention was abolished. Neostigmine induced HAPCs in both loop preparations. Pirenzipine (M1 antagonist) reduced ileal contractile activity in all loops and reduced colonic relaxation during ileal distention in innervated loops. Pirenzipine also reduced colonic tone and colonic HAPCs, more in denervated loops. Darifenacin (M3 antagonist) reduced ileocolonic contractile activity and tone more than did AF-DX 116 (M2 antagonist) in all loops. Cholinergic receptor subtypes modulate different facets of ileocolonic motor activity in the canine ileocolonic region. Increased sensitivity at M1 muscarinic receptors may partly account for the effects of extrinsic denervation.

Model of rapid gastrointestinal transit in dogs: effects of muscarinic antagonists and a nitric oxide synthase inhibitor

Our aims were to establish a canine model of rapid gastrointestinal transit, and to test the effects of muscarinic receptor antagonists (atropine, pirenzepine, AF-DX116, and darifenacin), and an NOS inhibitor, L-nitro-N-arginine (L-NNA) in this model. For gastric emptying and small bowel transit, 99mTc-labelled DTPA were added to a meal of skimmed milk (236 mL) that contained 2.4 g of magnesium hydroxide. Regional colonic transit was measured by111In-labelled beads placed in a capsule that released isotope in the proximal colon. Scintiscans were taken at regular intervals and indices of transit were calculated. Drugs were administrated intravenously. Gastric emptying, small bowel and colonic transit were rapid. Atropine and darifenacin (a selective M3 antagonist) delayed gastric emptying and colonic transit, the selective M1 and M2 muscarinic antagonists did not. The muscarinic blockers did not slow small bowel transit. L-NNA delayed small bowel and colonic transit but did not slow gastric emptying. A model suitable for the preclinical study of antidiarrhoeals was established. M3 receptors are important in the control of gastric emptying and colonic transit, and NOS inhibition slowed small bowel and colonic transit.

Direct clinical evidence for spinal hyperalgesia in a patient with irritable bowel syndrome

OBJECTIVE

Our objective was to evaluate GI motor and sensory function and spinal cord testing in a patient with severe irritable bowel syndrome.

METHODS

A patient is described who underwent an extensive assessment of GI motor and sensory function including transit studies, colonic and rectal barostat studies, sensory and manometric studies of the small bowel, and colon and anorectal physiology testing. The patient also underwent testing with spinal cord stimulation and spinal drug delivery as part of a pain management assessment.

RESULTS

The viscerosomatic referral pain pattern resulting from rectal distention was consistent with spinal hyperalgesia. The patient underwent testing for spinal cord stimulation and spinal drug delivery.

CONCLUSION

This novel finding provides direct clinical evidence for the presence of spinal hyperalgesia in a patient with irritable bowel syndrome, consistent with the existing indirect clinical evidence and animal data.

Rectal compliance, capacity, and rectoanal sensation in fecal incontinence

OBJECTIVE

Assessments of the pathophysiology of fecal incontinence are skewed toward anal sphincter function; however, rectal compliance, rectoanal sensation and capacity may also be relevant. The aim of this study was to evaluate the usual and some novel diagnostic approaches in fecal incontinence.

METHODS

In 22 unselected patients with fecal incontinence (21 F, 33-75 yr), we quantified: 1) symptoms, anorectal manometry, and anal ultrasound; 2) anal perception of temperature and light touch; 3) rectal sensitivity and compliance to distension; and 4) rectal reservoir function. Control values were obtained from two groups of 11 (seven F, 32-53 yr), and 32 (18 F, 19-44 yr) volunteers.

RESULTS

Patients had urge (14), passive (four), or combined (four) fecal incontinence; symptoms were mild in three, moderate in nine, and severe in 10 patients. Most had low sphincteric pressures and ultrasonic abnormalities. Temperature perception was impaired (p < 0.05) in incontinent patients, to a greater extent in the proximal anal canal and in patients with passive, as opposed to urge, incontinence. Intraluminal pressures for sensations of rectal distension were lower in incontinent patients (p = 0.02). Artificial stools elicited sensations of rectal filling at lower volumes than did a barostat bag, and in patients with urge, as opposed to passive, incontinence. In patients and controls, the sensation of urgency was associated (r2 = 0.2, p < 0.01) with rectal compliance.

CONCLUSIONS

We confirm that temperature sensation is impaired, and perception of rectal distension is not always reduced in fecal incontinence. Artificial stool tended to induce sensations at lower volumes than did balloon inflation. Altered sensory mechanisms may contribute to the pathophysiology of fecal incontinence.

Guidelines for adults on self-medication for the treatment of acute diarrhoea

Acute uncomplicated diarrhoea is commonly treated by self-medication. Guidelines for treatment exist, but are inconsistent, sometimes contradictory, and often owe more to dogma than evidence. An ad hoc multidisciplinary group has reviewed the literature to determine best practice. In general it is recognized that treatment of acute episodes relieves discomfort and social dysfunction. There is no evidence that it prolongs the illness. Self-medication in otherwise healthy adults is safe. Oral loperamide is the treatment of choice. Older anti-diarrhoeal drugs are also effective in the relief of symptoms but carry the risk of unwanted adverse effects. Oral rehydration solutions do not relieve diarrhoea, and confer no added benefit for adults who can maintain their fluid intake. Probiotic agents are, at present, limited in efficacy and availability. Antimicrobial drugs, available without prescription in some countries, are not generally appropriate for self-medication, except for travellers on the basis of medical advice prior to departure. Medical intervention is recommended for the management of acute diarrhoea in the frail, the elderly (> 75 years), persons with concurrent chronic disease, and children. Medical intervention is also required when there is no abatement of the symptoms after 48 h, or when there is evidence of deterioration such as dehydration, abdominal distension, or the onset of dysentery (pyrexia > 38.5 degrees C and/or bloody stools).

Characteristics and evolution of extraintestinal manifestations associated with ulcerative colitis after proctocolectomy

AIMS

Describe the characteristics of extraintestinal manifestations complicating ulcerative colitis present preoperatively and determine their evolution after surgery.

METHODS

Between 1976 and 1986, 281 patients with ulcerative colitis exhibiting one or more extraintestinal manifestations (EIM) before either IPAA (n = 147), Brooke ileostomy (n = 71), Kock pouch (n = 48) or ileorectostomy (n = 15) were assessed retrospectively. The clinical evolution of each manifestation was classified as having disappeared, improved, remained unchanged or aggravated postoperatively. An efficacy index was designed to assess the ratio of the number of cases cured or improved over the number of cases unchanged or aggravated. The relationship between EIM and gender, age, duration of disease and the type of surgery was also ascertained.

RESULTS

433 EIM were observed in 281 patients. The most common were arthralgias of the large joints (n = 146), of the sacroiliac joint (n = 59) and the small joints (n = 51). In comparison to patients without EIM having received the same operation during the same period of time, EIM were seen more often in women, younger patients, than those with longer duration of disease and the ileoanal anastomosis group. 60% had only one EIM at a time. Based on the efficacy index, thromboembolic accidents and erythema nodosum were the most commonly cured or improved. Ocular manifestations and primary sclerosing cholangitis were unaffected. The other EIM responded favorably but variably with improvement in two thirds of patients. The presence of a rectal remnant (IRA) or ileal reservoir did not affect the evolution of the EIM.

CONCLUSIONS

Thromboembolic complications which are life-threatening, erythema nodosum and arthralgia of the small and large joints which impair quality of life, benefited the most from proctocolectomy. Those conditions may be considered preoperatively when making the decision for surgery.

Increased eosinophil infiltration and degranulation in colonic tissue from patients with collagenous colitis

OBJECTIVE

Eosinophils infiltrate the colonic mucosa of patients with collagenous colitis (CC), although the pathogenetic implications are unknown, including whether these eosinophils are activated and degranulate in situ. We examined eosinophil infiltration and degranulation in the intestines of patients with CC by immunofluorescence for eosinophil granule major basic protein (MBP).

METHODS

We used both conventional histology (hematoxylin and eosin) and indirect MBP immunofluorescence histochemistry on colon biopsy specimens from patients with CC (n = 21) and from healthy controls (n = 9). Scoring of histological features was performed on hematoxylin and eosin-stained sections on a 0 to 3 scale. Eosinophil infiltration and degranulation, as quantified by extracellular MBP staining, were scored in each specimen on a 0 to 4 scale.

RESULTS

The inflammatory infiltrate of the lamina propria, the thickness of the collagen band, the numbers of intraepithelial lymphocytes, and degree of epithelial cell damage were all significantly increased in patients with CC as compared to controls (p < 0.0001). Scores for both eosinophil infiltration and degranulation were also significantly higher in the CC group compared to controls (p < 0.0001). The degree of infiltrating eosinophils by hematoxylin and eosin was correlated with eosinophil infiltration and degranulation by MBP immunostaining; however, no other correlations were found between eosinophil infiltration or degranulation by immunofluorescence and any of the histological parameters measured in the CC group.

CONCLUSIONS

Eosinophil infiltration and degranulation are increased in the colonic mucosa of patients with CC compared to healthy controls. Eosinophils and their cytotoxic granule proteins could be involved in the pathogenesis of CC. Further studies will be necessary to elucidate the mechanisms of eosinophil activation in CC.

Slow transit constipation

Slow transit constipation is a clinical syndrome predominantly affecting young women, characterized by constipation and delayed colonic transit, occasionally associated with pelvic floor dysfunction. The disorder spans a spectrum of variable severity, ranging from patients who have relatively mild delays in transit but who are otherwise indistinguishable from irritable bowel syndrome patients at one extreme, to patients with colonic inertia or chronic megacolon at the other extreme. Potential mechanisms for impaired colonic propulsion include fewer colonic HAPCs or a reduced colonic contractile response to a meal. The cause of the syndrome is unclear. The treatment is primarily medical; surgery is reserved for patients with severe disease or colonic inertia. Recognition and treatment of pelvic floor dysfunction is crucial for patients treated medically or surgically. Collaborative studies are necessary to determine the pathophysiology of this disorder and to ascertain the efficacy of novel prokinetic agents.

AGA technical review on constipation. American Gastroenterological Association

This literature review and the recommendations therein were prepared for the American Gastroenterological Association Clinical Practice and Practice Economics Committee. The paper was approved by the Committee on March 4, 2000, and by the AGA Governing Board on May 21, 2000.

American Gastroenterological Association Medical Position Statement: guidelines on constipation

This document presents the official recommendations of the American Gastroenterological Association (AGA) on constipation. It was approved by the Clinical Practice and Practice Economics Committee on March 4, 2000, and by the AGA Governing Board on May 21, 2000.

Concurrence of inflammatory bowel disease and multiple sclerosis

OBJECTIVES

To quantify the coexistence of inflammatory bowel disease (IBD) and multiple sclerosis (MS) and to characterize the diseases when they coexist.

PATIENTS AND METHODS

In this retrospective study of medical records spanning 1950 through 1995, the diagnoses of Crohn disease (CD), ulcerative colitis (UC), and MS were based on review of inpatient and outpatient records by a gastroenterologist and a neurologist.

RESULTS

We identified 4 residents of Olmsted County, Minnesota, with IBD (3 UC, 1 CD) who had concurrent, clinically definite MS; all had mild neurologic disease with little disability. These comprised 1% of the IBD and 1.8% of the MS cohort. The CD patient had undergone terminal ileal resection; of the UC patients, 2 had pancolitis, and 1 had proctosigmoiditis. The observed prevalence of MS at onset of IBD was 3.7 times the expected (95% confidence interval, 0.8-10.8). We also reviewed the records of 32 referral patients with both diagnoses. Disability from MS was moderate at median follow-up of 8.5 years. By 15 years, ambulation was impaired in most patients. Neurologic disability was similar between patients with CD and UC.

CONCLUSIONS

Concurrence of the 2 diseases was greater than expected. Although MS and IBD may share common predisposing factors, not enough information is available to speculate about possible mechanisms.

Motilides accelerate regional gastrointestinal transit in the dog

BACKGROUND

Motilides have prokinetic effects on the upper gut during fasting, increasing the strength of antral contractions and stimulating gastroduodenal phase 3 sequences. Effects on the distal gut, and postprandially, are less well documented.

AIM

To evaluate dose-response effects of motilin and erythromycin on gastric emptying, small bowel and colonic transit in the dog using a validated scintigraphic technique.

METHODS

For gastric emptying and small bowel transit, 99mTc labelled beads were added to a meal of dog chow (450 kcal). Regional colonic transit was measured by 111In labelled beads placed in a capsule which dissolved and released radiation into the proximal colon. Scintiscans were taken at regular intervals and indices of whole-gut transit were calculated. Drugs were given by slow intravenous administration.

RESULTS

In the doses used, motilin accelerated regional colonic transit but did not hasten gastric emptying or small bowel transit. Single or repeated doses of motilin had similar effects on colonic transit. Erythromycin accelerated gastric emptying, small bowel transit and regional colonic transit.

CONCLUSIONS

Motilin receptors are apparently present in the canine small bowel and colon. Postprandially, motilides accelerate transit in the distal gut.

Alcohol-related diarrhea

Abstract Alcohol generates a large caloric yield without supplying any essential nutrients; alcoholics may thus maintain body weight while suffering from malnutrition. In addition, diarrhea is a common complaint of both acute and chronic alcoholics. Here, we review the effects of alcohol on gastrointestinal morphology, function, its nervous system and motility. Acute morphological changes such as erosions, inflammatory cell infiltrations and microvascular changes are seen in the stomach and small intestine in acute alcoholics. In addition, atrophic gastritis, reduced villous height and decreased mucosal surface area of the small intestine have been described in chronic alcoholics. Acute administration of alcohol inhibits absorption of nutrients and fluids, and can stimulate secretion of water and electrolytes. Bacterial overgrowth in the proximal small intestine and decreased pancreatic secretions have been also described in chronic alcoholics. The well-known deleterious effects of alcohol on the central nervous system raise the possibility of similar acute and chronic effects of the enteric nervous system. Such effects could alter motility and transit. Indeed, esophageal dysmotility and delayed gastric emptying have been observed with high concentrations of alcohol in experimental studies and in chronic alcoholics. Small bowel motility and transit may be abnormal in both acute and chronic alcoholics, and colonic propulsive motility is increased after acute administration of alcohol. Any, or all, of these changes in gastrointestinal functions may contribute to diarrhea in acute binge drinkers and chronic alcoholics. Unfortunately, there is a lack of systematic studies of the pathophysiology of alcohol abuse, and an integrating concept of the diarrhea of alcoholics is still not possible.

Irritable bowel syndrome: making sense of it all

Though the basic science of the irritable bowel syndrome is far from certain, and the clinical science is often confusing, it is still possible to make some sense of the syndrome in a clinical context. These common complaints of altered bowel patterns, pain and bloating are extremely common and vary greatly in the impact they have on person's lives. From 'non-patients' who do not present for medical care to those who seek referral to multiple specialists, the spectrum is well known. If sense is to be made, the physician must understand the patient's major symptoms, how and to what degree they disturb their lifestyle, what is the patient's knowledge about and understanding of the syndrome, what has been done before, and why the patient is now presenting. What are the expectations and potential frustrations anticipated with this present consultation? A positive diagnostic approach can be taken but care is necessary to assuage lingering fears of organic disease, to correct misconceptions of the syndrome, to settle existing frustrations of the patient, and to educate. With these approaches, managing irritable bowel syndrome can be rewarding, though demanding.

Surreptitious laxative abuse: keep it in mind

The clinical example is one of diarrhea induced by the surreptitious use of laxatives. A 45-year-old man had a 3-year history of diarrhea, which had been fully investigated, without a cause having been identified. His general health appeared to be affected little, but he had the clinical features of an associated depressive illness. The diagnosis of laxative abuse was supported by the finding of abnormally high concentrations of magnesium in fecal water. He admitted initially, and later denied, the surreptitious ingestion of laxatives. This example is discussed with regard to features that were typical and atypical of the syndrome of laxative abuse. The significant points to be appreciated are 1) that any chronic, watery diarrhea that has eluded diagnosis after an adequate investigation is possibly self-induced, and 2) that awareness of this syndrome and its prevalence in selected cohorts can lead to direct and inexpensive documentation of the diagnosis.

The effects of biofeedback on rectal sensation and distal colonic motility in patients with disorders of rectal evacuation: evidence of an inhibitory rectocolonic reflex in humans?

OBJECTIVE

Abnormalities of descending colon motility reported in a subset of patients with rectal evacuation disorders are consistent with a rectocolonic inhibitory reflex. Our aims were to evaluate distal colon motor function and rectal sensation in such patients and assess effects of biofeedback (BF) training on these functions.

METHODS

Seven patients (five women, two men; mean age 36 yr) with rectal evacuation disorders were studied before and after 10-days biofeedback training; six healthy volunteers (five women, one man; mean age 30 yr) were studied once. Colonic compliance, motility, sensation thresholds, and perception scores during standardized rectal distentions were measured using two barostat-manometry assemblies inserted into the cleansed colon with the aid of flexible sigmoidoscopy.

RESULTS

Sigmoid compliance, fasting, and postprandial motility index, and perception thresholds were similar in controls and patients before and after biofeedback training. Postprandial sigmoid tone tended (p = 0.09) to be lower in patients than controls; after biofeedback, postprandial tone was comparable to that in controls. Rectal urgency scores at 24 mm Hg distention were greater in patients than in controls (p = 0.02 for both). After biofeedback, there were trends for lower perceptions of urgency to defecate (7.6 +/- 1.1 cm pre- vs 5.3 +/- 1.5 post-; p = 0.04) at 24 mm Hg; conversely, gas sensation at 12 mm Hg was higher (1.2 +/- 0.5 cm pre- vs 3.3 +/- 0.6 post-; p = 0.05).

CONCLUSIONS

Normalization of rectal evacuation and postprandial sigmoid tone in patients with evacuation disorders by biofeedback training supports the presence of a rectocolonic inhibitory reflex. Effect of biofeedback on rectal sensation in these patients requires further study.

Videoendoscopic diagnosis of esophageal motility disorders

BACKGROUND

Esophageal motility disorders are usually diagnosed by manometry. We evaluated videoendoscopy as a diagnostic test.

METHODS

In this study, 20 patients with achalasia, 13 with scleroderma, and 33 control subjects had a standard endoscopic examination followed by protocol videotaping of swallows to observe contractions in the esophagus and in the lower esophageal sphincter. Tapes were later reviewed by 2 blinded observers who recorded their motility findings and diagnoses.

RESULTS

In the mid esophagus at 25 cm, lumen-occluding peristaltic contractions were identified in 26 of 33 control subjects versus 1 of 20 achalasia (p < 0.001) and 3 of 13 scleroderma patients (p < 0.005). As viewed in the lower esophagus, the lower esophageal sphincter opened normally in 31 of 33 control subjects versus 1 of 20 achalasia (p < 0.001). In scleroderma, the sphincter never closed in 12 of 13 patients (p < 0. 001 versus control subjects). A diagnostic sequence of sphincter opening followed by contraction in the esophageal body and subsequent sphincter closing was seen in 33 of 33 control subjects, 2 of 20 achalasia, and 1 of 13 scleroderma patients (both, p < 0. 001). The observers made the correct diagnosis in 96% of cases.

CONCLUSIONS

Achalasia and esophageal scleroderma can be identified by endoscopic observation of motility. This procedure may represent an adjunctive diagnostic test to manometry.

Scintigraphic measurement of regional gastrointestinal transit in the dog

Scintigraphic techniques can measure sequentially gastric emptying, small bowel transit, and colonic transit in humans, and comparable methods for experimental studies in animals would be useful. We developed such a method in dogs and examined the effects of prokinetic drugs on regional transit. Two isotopes were given to fasting dogs. Polystyrene pellets labeled with 99mTc were mixed in a can of dog food and 111In- labeled pellets were given in a gelatin capsule coated with a pH-sensitive polymer, designed to dissolve in the distal bowel. Gamma camera images were obtained for up to 24 h. Prokinetic drugs were given by intravenous injection. Duplicate baseline studies showed good agreement in seven dogs. In a second group (n = 4), intra- and interanimal variabilities were established. Two novel prokinetic drugs (AU-116 and AU-130) accelerated small bowel and colonic transit. A simple noninvasive method for measuring whole gut transit in dogs was developed and validated. Two new prokinetics accelerated small bowel and colonic transit.

Effects of an irritable bowel syndrome educational class on health-promoting behaviors and symptoms

OBJECTIVE

The degree to which patient education in the areas of diet, exercise, and stress management can improve symptoms of irritable bowel syndrome (IBS) through healthier lifestyle behaviors is unknown. The aim of this study was to determine the effects of outpatient education on the short and long term outcomes, and the association between health-promoting behaviors and symptoms.

METHODS

Pender's Health Promotion Model provided the theoretical framework. The study had a prospective longitudinal design. A consecutive sample of 52 adult outpatients with IBS attended a structured class that taught health-promoting modifications of lifestyle. Participants completed the Health-Promoting Lifestyle Profile (HPLP) and selected items from a Bowel Disease Questionnaire (BDQ) before the class and 1 month and 6 months later. Spearman rank correlations were used to assess the association between HPLP and symptom scores. Wilcoxon rank sum tests compared changes in scores versus their baseline values.

RESULTS

Response rates at 1 and 6 months were 75% and 83%, respectively. Results revealed significant 1- and 6 month-improvements in pain and Manning symptoms (p < 0.01) and in some HPLP scores (exercise at 1 month, p < 0.05; stress management at 6 months, p < 0.01). Significant associations were found between some, but not all, HPLP and symptom scores over time.

CONCLUSION

A structured IBS educational class for patients with IBS improved symptoms and some health-promoting behaviors. However, relationships among specific behaviors and specific symptoms did not consistently correspond with this improvement.

Eosinophilia and gastrointestinal symptoms after ingestion of shiitake mushrooms

BACKGROUND

Shiitake mushrooms are a dietary staple in Asia and are increasingly popular worldwide. A cholesterol-lowering study with shiitake showed that 17 of 49 participants withdrew because of rash or abdominal discomfort, and two had marked eosinophilia. One of these latter participants was subsequently challenged for 14 days with shiitake powder and again had eosinophilia.

OBJECTIVE

We investigated whether ingestion of shiitake mushroom powder induces eosinophilia or symptoms.

METHODS

We studied 10 normal persons. Each participant ingested 4 gm shiitake powder (open label) daily for 10 weeks (trial 1), and the protocol was repeated in these same subjects after 3 to 6 months (trial 2). Blood counts and serum samples were obtained biweekly (trial 1) or weekly along with stool specimens (trial 2). Eosinophil major basic protein and IL-5, IgE, and IgG antishiitake antibodies were measured in sera. Eosinophil-derived neurotoxin was measured in stool extracts. We defined responders as subjects having peak eosinophil counts four or more times their average baseline counts.

RESULTS

Each trial had four responders, and trial 2 had one new and three repeat responders. Eosinophilia ranged from 400 to 3900/mm3. Responders had increased blood eosinophils, serum major basic protein, stool eosinophil-derived neurotoxin, and factors that enhanced eosinophil viability. Antishiitake IgE was not detected, and antishiitake IgG increased in two responders. Gastrointestinal symptoms coincided with eosinophilia in two subjects. Symptoms and eosinophilia resolved after discontinuing shiitake ingestion.

CONCLUSIONS

Daily ingestion of shiitake mushroom powder in five of 10 healthy persons provoked blood eosinophilia, increased eosinophil granule proteins in serum and stool, and increased gastrointestinal symptoms. Shiitake ingestion suggests a model to study the eosinophil's role in the blood and gastrointestinal tract. Finally, our report raises concerns of possible adverse systemic reactions to this increasingly popular food.

Rectal tone, distensibility, and perception: reproducibility and response to different distensions

Increasing interest is focusing on the role of intestinal tone, distensibility, and mechanosensation in the genesis of abdominal symptoms. Experimental approaches usually feature balloon distension of the bowel with measurements of perception, tone, and compliance and/or elastance; however, the methodologies are standardized incompletely. We examined the reproducibility of repeated assessments of sensory perception, basal tone, and compliance and/or elastance of the rectum during distension. We also evaluated the response to inflations that varied in regard to control of pressure or volume, pattern of distension, and rate of inflation. Five healthy volunteers were studied under two separate protocols. The first featured a series of experiments on each of 5 days; the other consisted of 2 separate days of study. Repeated distensions evoked reproducible responses of sensation and compliance and/or elastance on a single day, providing a conditioning distension preceded them. Day-to-day variability was also sufficiently small to allow valid comparisons to be made on different days in healthy persons. The configuration of the distension profile (phasic, staircase, or ramp) and the rate of inflation (from 1 to 40 ml/s) had little effect on distensibility or perception. Perceptions were sometimes transient and sometimes constant, but no relationship was found between these temporal features and the magnitude of the stimulus. These observations help provide a basis as to how the responses to rectal distension can be best studied.

Preoperative perfusion of bypassed ileum does not improve postoperative function

This study evaluated whether twice daily isotonic perfusion of the bypassed ileum for six weeks would enhance its motor activity and its absorption of fluids, electrolytes, and vitamin B12. The study also determined if patients undergoing perfusion had improved bowel function and decreased hospital stay after ileostomy closure. Following proctocolectomy, ileal pouch-anal canal anastomosis, and diverting loop ileostomy, six patients self-infused an isotonic solution (sucrose and sodium chloride) into the bypassed ileum twice daily, while seven patients did not (controls). Two months following proctocolectomy, and just prior to ileostomy closure, a manometric catheter assembly was placed into the unused distal ileum via the stoma and the distal ileum perfused with an isotonic sodium chloride solution for 3 hr during fasting and 3 hr after a meal. Absorption was measured, single and clustered pressure waves were identified, and a motility index was calculated. Water absorption, motility index, and cluster parameters did not improve in perfused patients compared to controls during fasting or after a meal, nor did perfused patients have improved vitamin B12 absorption. The perfused patients also did no better clinically following ileostomy takedown; the onset of bowel movements, their frequency, time to tolerate a diet, and hospital stay were similar to controls. We conclude that six weeks of twice daily isotonic perfusion did not improve motor activity or water, electrolyte, and vitamin B12 absorption in the bypassed distal ileum after proctocolectomy, ileal pouch-anal canal anastomosis, and loop ileostomy. The perfusion also did not improve bowel function after ileostomy takedown.

Duodenal motility in fasting dogs: humoral and neural pathways mediating the colonic brake

We have previously described a negative feedback loop that inhibits duodenal motility when nutrients are infused into the ileum and colon. In the present study, we examined the role of extrinsic innervation and plasma levels of peptide YY (PYY) in mediating this phenomenon. We perfused neurally intact (n = 5 dogs) or extrinsically denervated (n = 6 dogs) isolated loops of proximal colon with isomolar NaCl or a mixed-nutrient solution at 2 and 6 ml/min for 4 h during fasting or for 2 h beginning 15 min after a meal. Both rates of infusion with NaCl prolonged the cycle length of the duodenal migrating motor complex (MMC) in the group with neurally intact loops but not in the group with extrinsically denervated loops. Nutrient infusions increased the MMC cycle length in both groups. Integrated plasma concentrations of PYY were increased by nutrients but not by NaCl in both groups. These data suggest that increased volumes and unabsorbed nutrients in the proximal colon alter proximal small bowel motility. Volume-induced effects are mediated via extrinsic nerves, whereas nutrient-induced effects may be mediated by humoral factors, such as plasma PYY.

Pharmacological modulation of rectal tone alters perception of distention in humans

OBJECTIVE

Drugs can alter perception of balloon distention of the GI tract. It has been proposed that the mechanism by which this occurs is through effects on visceral afferent pathways. Our hypothesis was that modulation of rectal tone will also influence the perception of rectal balloon distention.

METHODS

Fasting and postprandial rectal tone, compliance, and perception of rectal distention were measured in 25 healthy subjects, using a five-armed, parallel, single-blinded study design. Each subject received either glucagon, nitroglycerin, clonidine, yohimbine, or saline.

RESULTS

Rectal tone, but not compliance, influenced perception as measured by balloon distention of the rectum (r = 0.6, p = 0.002). Glucagon, nitroglycerin, and clonidine reduced and yohimbine increased fasting tone compared with saline. Compliance and postprandial tone were similar in all groups. Yohimbine increased rectal perception of distention.

CONCLUSIONS

Tone is one of the factors that influences the sensory perception of balloon distention in the human rectum. Alpha2-adrenergic agents, a nitric oxide donor, and glucagon altered fasting rectal tone, but postprandial tone was similar after administration of each agent.

Dexpanthenol enemas in ulcerative colitis: a pilot study

OBJECTIVE

To test the hypothesis that topical administration of pantothenic acid, a precursor of coenzyme A, might result in increased tissue levels of coenzyme A, improvement of fatty acid oxidation, and amelioration of ulcerative colitis.

MATERIAL AND METHODS

In an open-label pilot study, three patients with active left-sided ulcerative colitis received nightly enemas that contained 1,000 mg of dexpanthenol for 4 weeks. Before and after the study, patients submitted stool specimens for short-chain fatty acid analysis and urine collections for measurement of pantothenic acid and dicarboxylic acids; they also underwent flexible sigmoidoscopy for procurement of biopsy specimens for histologic examination and measurement of colonic coenzyme A activity. A clinical disease activity index and histologic disease activity index were used to assess response.

RESULTS

Despite increases in urinary pantothenic acid, no significant changes were found in colonic tissue coenzyme A concentrations, fecal short-chain fatty acid concentrations, or urinary dicarboxylic acid concentrations. Moreover, no significant changes in clinical or histologic disease activity were noted. Although stool frequency and rectal bleeding remained unchanged, all patients noted increased abdominal cramping, and one patient had an increased extent of disease.

CONCLUSION

Topically administered dexpanthenol seems to be absorbed, but at the dose used in this study, it did not influence concentrations of colonic coenzyme A activity, fecal short-chain fatty acids, or clinical response in patients with active left-sided ulcerative colitis.

Rapid gastric emptying in patients with functional diarrhea

OBJECTIVE

To analyze our experience in patients with chronic diarrhea by using a noninvasive transit study that measures gastric emptying as well as small bowel and colonic transit.

MATERIAL AND METHODS

Results from 94 consecutive transit tests, for which diarrhea was the main indication, were reviewed and correlated with the final classification of patients as having an organic or nonorganic disorder.

RESULTS

Sixty patients were considered to have a nonorganic cause of diarrhea, of whom 15 had previously undergone cholecystectomy. The other 34 patients were considered to have diarrhea on the basis of an organic diagnosis. Gastric emptying was more often rapid in patients with a nonorganic cause (P < 0.05), but not if cholecystectomy had been performed previously. Small bowel transit was fast more often in patients with organic diarrhea than in those with no organic cause of the diarrhea (P < 0.05); colonic transits showed no significant differences among groups.

CONCLUSION

The findings implicate a motor abnormality of the upper gut, rapid gastric emptying, as a pathophysiologic mechanism of functional bowel disorders with diarrhea. The results imply that additional prospective observations should be worth-while.

Increased eosinophil granule proteins in gut lavage fluid from patients with inflammatory bowel disease

OBJECTIVE

To explore the potential role of eosinophils in the pathogenesis of inflammatory bowel disease (IBD).

DESIGN

We measured the concentrations of eosinophil granule proteins-namely, major basic protein, eosinophil peroxidase, eosinophil cationic protein, and eosinophil-derived neurotoxin-in gut lavage fluid.

MATERIAL AND METHODS

Ten healthy persons and 17 patients with IBD (9 with Crohn's disease and 8 with ulcerative colitis) underwent gut lavage. Each study subject submitted an early specimen when lavage effluent became liquid and a late specimen when the output became clear. The concentrations of the granule proteins were measured by immunoassay.

RESULTS

The median concentrations of eosinophil-derived neurotoxin and eosinophil cationic protein were significantly higher in patients with IBD than in control subjects for both early and late lavage specimens. Excretion of eosinophil peroxidase was also significantly higher in patients with IBD than in the healthy control subjects, but only in the early specimens. No differences were noted in the concentrations of any of the proteins between patients with ulcerative colitis and those with Crohn's disease.

CONCLUSION

Concentrations of eosinophil granule proteins were increased in whole gut lavage fluid from patients with IBD in comparison with healthy control subjects. These results encourage further studies of the role of eosinophils in the pathogenesis of IBD.

Motility and tone of the left colon in constipation: a role in clinical practice?

OBJECTIVES

Colonic motor mechanisms deranged in constipation are not understood completely. Our aim was to measure left colonic motility and tone, during fasting and postprandially in patients with chronic constipation.

METHODS

During 1 h fasting and 2 h postprandially, we measured pressures (multilumen manometry) and tone (barostat) in the left colon of 15 healthy controls and 40 patients with chronic constipation associated with slow (n = 15) or normal colonic transit (n = 12) or outlet obstruction (n = 13).

RESULTS

Fasting tone was similar in all groups, and all demonstrated a significant increase in motor activity to food. There was lower postprandial tone (p < 0.05) in the slow transit and outlet obstruction groups. There were no differences in the timing of the tonic response or the number or amplitude of high-pressure propagated contractions. The slow transit group had lower postprandial phasic responses in the rectosigmoid (p < 0.05) and descending (p < 0.1) colon; the outlet obstruction group had lesser descending (p < 0.05) and rectosigmoid (p < 0.1) colon phasic motility.

CONCLUSIONS

Colonic intraluminal measurements alone do not discriminate subgroups of chronic constipation more accurately than transit and pelvic floor tests, and currently have a limited role in clinical practice. However, manometry and tone measurements may be helpful in confirming a diagnosis of slow transit constipation (colonic inertia) in patients considered candidates for surgical treatment.

Variability of gastrointestinal transit in healthy women and men

BACKGROUND AND AIMS

Measurements of gastrointestinal transit are made in clinical and research gastroenterology, yet their intrinsic variability is not well characterised. In particular, an influence of hormones on transit has been proposed as the basis for gastrointestinal symptoms that vary with the menstrual cycle. Our aims were to quantify individual differences in transit during the menstrual cycle in healthy women and to compare these with the intrinsic variability in healthy men.

METHODS

On two occasions, whole gut transit was assessed scintigraphically and colonic transit quantified by radio-opaque markers. Thirty two healthy volunteers (12 women, 20 men) were studied, women during the follicular and luteal phases, men twice within a similar four week period. Diets and exercise were standardised prior to and during both studies.

RESULTS

Colonic transit was significantly faster in men, and postlag gastric emptying was also more rapid; other indices of regional transit were not different between the sexes. Total colonic transit time was equally well reflected by the scintigraphic and radio-opaque marker methods. Important intraindividual differences were noted in both sexes. The variances in our samples predicted an 80% chance of detecting (with 95% confidence) a mean effect of menstrual hormones on transit that was in the same range as the intrinsic variation in men.

CONCLUSIONS

Colonic transit was faster in men than in women. Although group means in the two studies were almost identical, single assessments of transit in subjects sometimes exhibited considerable variability, implying broad biological variations. Given this intrinsic variability, the influence of menstrual hormones on gastrointestinal transit must be small and of doubtful clinical significance.

Changing referral patterns for surgical treatment of ulcerative colitis

OBJECTIVE

To determine whether referral patterns for surgical treatment among patients with chronic ulcerative colitis have changed in recent years, especially in view of the introduction of a new operation, the ileal pouch-anal anastomosis (IPAA).

MATERIAL AND METHODS

Between January 1976 and December 1986, 981 patients underwent proctocolectomy at Mayo Clinic Rochester. Brooke ileostomy (N = 300), colectomy with ileorectal anastomosis (N = 33), proctocolectomy with Kock pouch (N = 180), or ileal pouch-anal anastomosis (IPAA) (N = 468) was performed. The indications for surgical intervention were categorized as emergent or elective, the latter including intractability, cancer, and cancer prophylaxis. For analysis, the duration from diagnosis of disease to operation, indications for surgical treatment, and types of operation were subdivided into pre-IPAA era (before 1981) and post-IPAA era (from 1981 onward) for the entire group and for distant versus local patients.

RESULTS

More continence-preserving operations were done in 1981 and thereafter (76%) than before 1981 (46%). In the later segment of the study period in comparison with before 1981, fewer operations were done for emergent reasons (4% versus 8%) and a greater percentage of operations were done for elective indications, especially intractability (74% versus 61%). With the advent of IPAA in 1981, patients underwent operation sooner after the diagnosis was made (7.4 years versus 8.6 years before 1981). A smaller proportion of patients underwent operation for cancer prophylaxis during 1981 through 1986 (19%), however, than before 1981 (28%).

CONCLUSION

Referral patterns for surgical treatment of patients with ulcerative colitis have changed in recent years--patients are being referred for operation sooner, before complications develop that necessitate emergent procedures. Although the changed referral pattern may be due to the availability of IPAA, other factors may also have a role.

How well does stool form reflect colonic transit?

BACKGROUND

Watery stools are equated with rapid and hard stools with slow intestinal transit; however, the relation between stool form and transit through specific regions of the gut is not clear cut. In addition, more information is needed on interindividual variability of these measurements.

AIM

To examine the relations between stool form and gastric emptying, small bowel and colonic transit.

METHODS

Regional gut transit was assessed scintigraphically and segmental colonic transit was also quantified by radio-opaque markers. On two occasions, 32 healthy volunteers (12 men, 20 women) were studied, women during the follicular and luteal phases of menstruation, men twice within a similar four week period. Diets were standardised and stool form was recorded on a seven point scale.

RESULTS

Women had significant harder stools; hard stools were correlated significantly with slow transit and loose stools with fast transit through the colon.

CONCLUSIONS

Stool form could not be related to gastric emptying or small bowel transit.

Methods for studying intestinal sensitivity and compliance: in vitro studies of balloons and a barostat

The aim of this study was to compare in vitro various methods for recording intestinal sensitivity and compliance. Relationships between volume and pressure were determined in segments of penrose tubing and pig gut ("artificial intestine') using pressure increments of 2 mmHg (0-24 mmHg). We tested two direct methods of distension of the entire segments (by syringe inflation and the Mayo barostat); we also used three different balloon devices for indirect distension (a 10 cm polyethylene barostat bag, a 10 cm latex condom balloon and a 6 cm latex condom balloon). Maximal distending diameters of the recording systems were measured by injecting from 0 to 160 mL of air. The elastic properties of the balloons were also tested by distensions in air and in rigid tubes. All recording systems accurately detected a lesser compliance of the penrose drain as compared to pig gut. In absolute terms, only the compliance measured with a polyethylene barostat bag distended with a syringe was not different from the compliance of the segment as measured directly. The bellows of our barostat and the latex balloons had significant intrinsic compliances which interfered with the recorded pressure-volume curves. On the other hand, highly compliant plastic bags recorded most faithfully the compliance of artificial gut and that of non-compliant rigid tubes. For comparable volumes of distension, external diameters were larger with the 6 cm latex balloon than with the 10 cm latex balloon or the 10 cm polyethylene barostat balloon. A polyethylene bag distended with a non-compliant air injector (syringe) reflected most accurately the pressure-volume relationships of tubular structures. The different maximal diameters assumed by the three distending devices may explain, in part, why lower volumes of distension are required to elicit symptoms with smaller distending balloons in vivo.

Colonic motility in health and disease

Being the final pathway for chyme and digestive residues, the colorectum influences bowel function critically. The most important and relevant symptoms of colonic dysfunction are diarrhea, constipation, urgency, and pain. Despite the effects of many investigators, over several decades, the motor physiology of the human colon is still relatively obscure. Most is known about patterns of colonic transit. In practice, measurements of transit are the best characterized and most widely available tests of colonic motor function. Colonic hypersensitivity, implying an abnormality of afferent signaling, is assuming greater importance in the pathophysiology of conditions as common as IBS and inflammatory bowel disease.

Constipation and fecal incontinence in the elderly population

OBJECTIVE

To describe the assessment and management of constipation and fecal incontinence in elderly patients.

DESIGN

We reviewed pertinent publications in the recent medical literature and outlined effective management strategies for constipation and fecal incontinence in the geriatric population.

RESULTS

Constipation can be classified into two syndromes--functional constipation and rectosigmoid outlet delay. Evaluation consists of elicitation of a detailed history, directed physical examination, and selected laboratory tests. Management involves nonpharmacologic (such as exercise and fiber) and pharmacologic measures. Fecal incontinence in elderly patients can be due to stool impaction, medications, dementia, or neuromuscular dysfunction. Management options include modification of contributing disorders, pharmacologic therapy, and behavioral techniques.

CONCLUSION

Constipation and fecal incontinence are common and often debilitating conditions in elderly patients. Management should be highly individualized and dependent on cause, coexisting morbidities, and cognitive status.

PYY and GLP-1 contribute to feedback inhibition from the canine ileum and colon

To explore mechanisms whereby unabsorbed nutrients in the ileum inhibit the upper gut ("ileal brake"), we perfused the canine ileum or colon and monitored phase 3 in the duodenum. Fasting motility was recorded when the ileum or colon was perfused with 154 mM NaCl, a mixed isotonic nutrient solution (Ensure), or individual nutrients (maltose, casein hydrolysates, or sodium oleate). Blood samples were collected before and during the perfusions. The ileum was also perfused with 154 mM NaCl while peptide YY (PYY) was infused by vein. In both sets of experiments, plasma levels of PYY, neurotensin, and glucagon-like peptide-1 (GLP-1) were measured. Ileal or colonic perfusion of Ensure delayed phase 3 [migrating motor complexes (MMC)] in the duodenum, inhibited ileal motility, and increased plasma levels of PYY and GLP-1. Ileal casein and oleate and colonic casein also delayed the duodenal MMC. The MMC cycle length and plasma levels of PYY were closely correlated. Intravenous PYY prolonged the MMC cycle; an intravenous dose of 100 pmol.kg-1.h-1 of PYY mimicked the effects of ileal Ensure. These results support the hypothesis that PYY, and possibly GLP-1, participate in the ileal brake. This negative feedback loop also affects the distal small bowel. The proximal colon also triggers the feedback inhibition of gut motility (colonic brake).

Endoscopic esophageal manometry

OBJECTIVE

We performed through-the-scope-manometry of the esophagus on 12 patients referred for esophageal symptoms.

METHODS

A 3-lumen polyvinyl tube was passed through the biopsy channel of a standard video-endoscope. All patients underwent esophagogastroduodenoscopy with through-the-scope-manometry as well as a conventional laboratory-based manometric study; the sequence of the procedures was randomized.

RESULTS

Mean lower esophageal sphincter pressure was 18 +/- 11 mm of mercury by both methods. In the lower esophagus, mean wave amplitude was 60 +/- 25 mm of mercury by through-the-scope manometry and 82 +/- 28 by laboratory testing. In the upper esophagus, mean wave amplitude was 50 +/- 26 mm of mercury by through-the-scope manometry and 63 +/- 20 by laboratory testing. Wave duration tended to be lower by through-the-scope manometry than by laboratory testing in the lower and upper esophagus. In nine patients with normal esophageal motility, 54% of swallows resulted in a peristaltic wave by the endoscopic study versus 100% for the laboratory test.

CONCLUSION

Through-the-scope-manometry was able to accurately measure lower esophageal sphincter pressure compared with laboratory-based manometry. Peristaltic wave amplitude by through-the-scope manometry was reduced compared with laboratory-based manometry, most likely because of the use of dry swallows. Through-the-scope-manometry has promise as a screening test for esophageal motility disorders.

Effects of ethanol, xylose, and glucose on canine jejunal motility

Ethanol is an important source of calories that can cause certain gastrointestinal symptoms, notably diarrhea. To examine the effects of ethanol on the small bowel, we intraluminally perfused the jejunum of four dogs with ethanol (18, 9, 4.5, and 1.5%, wt/vol), D-xylose (30, 15, 7.5, and 4.5%, wt/vol), or glucose (30 and 5%, wt/vol). In other experiments, these solutes were infused intravenously. Saline was always given by the alternate route; jejunal manometry was recorded during and after the infusions. Phase III of the interdigestive cycle was delayed by all intraluminal infusions except for 4.5 and 1.5% ethanol, 4.5% xylose, and 5% glucose. In addition, the onset of irregular contractile activity was delayed more with intraluminal ethanol than with intraluminal xylose or intraluminal glucose (P < 0.01). When administered intraluminally, ethanol and xylose appeared in blood but only ethanol equilibrated fully between the lumen and blood. Intravenous infusions of ethanol and xylose, but not glucose, also delayed the return of phase III. When given intravenously, ethanol and xylose were recovered from the lumen, whereas glucose never was. Ethanol and xylose had comparable effects on the canine small bowel; they induced prolonged periods of irregular contractile activity and delayed the return of phase III. These effects were seen rapidly when solutes were administered intraluminally and more slowly when they were given intravenously. These results suggest that local luminal mechanisms stimulated by solutes influence small bowel motility, and they imply that the gut recognizes solutes whether or not these molecules are metabolizable.

Fecal bile acids, short-chain fatty acids, and bacteria after ileal pouch-anal anastomosis do not differ in patients with pouchitis

Construction of an ileal reservoir changes the fecal bacterial flora and the fecal composition of bile acids and short-chain fatty acids. We examined the relationships between pouch inflammation (pouchitis) and pouch content, as assessed by analysis of fecal bacteria, bile acids, and short chain fatty acids. Four groups were studied: ileal pouch-anal anastomosis (IPAA) for ulcerative colitis with pouchitis (N = 10), IPAA without pouchitis (N =5), IPAA for familial adenomatous polyposis without pouchitis (N = 5); and Brooke ileostomy for ulcerative colitis, which served as controls (N = 5). Pouchitis was defined as > or = 7 points on an 18-point pouchitis disease activity index. Aerobic and anaerobic bacteria were quantitatively cultured. Total aqueous-phase bile acids were measured by thin-layer chromatography and an enzymatic 3 alpha-OH hydroxysteroid dehydrogenase method. Fecal short chain fatty acids were measured by gas liquid chromatography. All patients with an IPAA had higher ratios of anaerobes/aerobes and concentrations of anaerobic gram-negative rods than did patients with an ileostomy. There were no other differences between patient groups with respect to bacteria, aqueous-phase total bile acids, or fecal short-chain fatty acids. Fecal concentrations of bacteria, bile acids, and short-chain fatty acids were similar in patients with and without pouchitis, indicating that these factors can not be the sole cause of pouchitis.

Visceral perception in irritable bowel syndrome. Rectal and gastric responses to distension and serotonin type 3 antagonism

We wished to determine if visceral perception in the rectum and stomach is altered in patients with irritable bowel syndrome and to evaluate the effects on visceral sensation of 5-HT3 receptor blockade. Twelve community patients with diarrhea-predominant irritable bowel syndrome and 10 healthy controls were studied in a double-blind, randomized, placebo-controlled study. Using two barostats, the stomach and rectum were distended, with pressure increments of 4 mm Hg, from 10 to 26 mm Hg; visceral perception was measured on an ordinal scale of 0-10. Personality traits were measured using standard psychological methods, and somatic pain was evaluated by immersion of the nondominant hand in cold water. The effect of 5-HT3 antagonism was tested with a single intravenous dose of ondansetron at 0.15 mg/kg. Gastric perception was higher in irritable bowel syndrome, but rectal distension was perceived similarly in irritable bowel syndrome and controls. Pain tolerance to cold water was also similar in irritable bowel syndrome and controls. Ondansetron induced rectal relaxation and increased rectal compliance but did not significantly alter gastric compliance or visceral perception. Psychological test scores were similar in patients and controls. We conclude that in this group of psychologically normal patients with irritable bowel syndrome, who were not chronic health-care seekers, visceral perception was normal. Ondansetron did not alter gut perception in health or in irritable bowel syndrome.

Scintigraphy of the whole gut: clinical evaluation of transit disorders

OBJECTIVE

To describe an initial clinical experience with a noninvasive scintigraphic technique for assessing gastrointestinal motility.

DESIGN

We studied gastric, small bowel, and colonic transit in 109 unselected patients encountered between June and December 1992 at the Mayo Clinic.

MATERIAL AND METHODS

The study patients were categorized on the basis of major complaint (constipation in 46, upper gastrointestinal symptoms in 45, and diarrhea in 18) and presence or absence of an underlying organic disease. Radioscintigraphy was used to analyze various regions of the gastrointestinal tract; scans were obtained at 2, 4, 6, and 24 hours after ingestion of a radiolabeled test meal.

RESULTS

Overall, patients with a main complaint of constipation usually had slow or normal gastric, small bowel, and colonic transit, whereas those with diarrhea as the major symptom usually had normal or fast results of these studies. In the 65 patients with no underlying organic disease, inconsistent patterns of gastric emptying and small bowel and colonic transit were noted.

CONCLUSION

Our results suggest that this 24-hour scintigraphic test may be clinically useful in screening for dysmotility syndromes in patients with nausea, vomiting, diarrhea, or constipation.

The diverse spectrum of irritable bowel syndrome

The cardinal symptoms of IBS are abdominal pain and either diarrhea or constipation. Two cases with very different presentations illustrate a simplified diagnostic workup and provide practical suggestions for management. Patients can expect substantial benefits from treatment, provided they are willing to participate in its execution.

Scintigraphy of the whole gut: clinical evaluation of transit disorders

OBJECTIVE

To describe an initial clinical experience with a noninvasive scintigraphic technique for assessing gastrointestinal motility.

DESIGN

We studied gastric, small bowel, and colonic transit in 109 unselected patients encountered between June and December 1992 at the Mayo Clinic.

MATERIAL AND METHODS

The study patients were categorized on the basis of major complaint (constipation in 46, upper gastrointestinal symptoms in 45, and diarrhea in 18) and presence or absence of an underlying organic disease. Radioscintigraphy was used to analyze various regions of the gastrointestinal tract; scans were obtained at 2, 4, 6, and 24 hours after ingestion of a radiolabeled test meal.

RESULTS

Overall, patients with a main complaint of constipation usually had slow or normal gastric, small bowel, and colonic transit, whereas those with diarrhea as the major symptom usually had normal or fast results of these studies. In the 65 patients with no underlying organic disease, inconsistent patterns of gastric emptying and small bowel and colonic transit were noted.

CONCLUSION

Our results suggest that this 24-hour scintigraphic test may be clinically useful in screening for dysmotility syndromes in patients with nausea, vomiting, diarrhea, or constipation.

Evaluation of an inexpensive screening scintigraphic test of gastric emptying

Our goal was to study the accuracy of a limited assessment relative to the traditional and obtain a more detailed approach to measure gastric emptying.

METHODS

We prospectively evaluated 35 patients referred to our laboratory with suspected fast or slow gastric emptying. Transit was measured radioscintigraphically after ingestion of an egg meal containing 99mTc-Amberlite pellets. Gastric emptying was analyzed by power exponential analysis. Diagnostic accuracy of simpler indices (gastric residual at 2 and 4 hr) was determined by comparing the categorization of patients as normal or abnormal relative to previously published normal data from our laboratory.

RESULTS

Gastric residual at 2 hr showed greater diagnostic accuracy for accelerated gastric emptying with 90% sensitivity at 90% specificity. Gastric residual at 4 hr was less accurate for accelerated emptying, but was more accurate at detecting delayed gastric emptying with 100% sensitivity at 70% specificity. In contrast, sensitivity and specificity of gastric residual at 2 hr for slow emptying were low (100% sensitivity with 20% specificity) emphasizing the importance of obtaining a scan later than 2 hr for detecting delayed gastric emptying.

CONCLUSION

Selective scans taken at 2 and 4 hr provide an excellent screening test for detecting fast or slow gastric emptying; the accuracy of 2-hr data is optimal for accelerated emptying and that of the 4-hr data greater for delayed emptying. This strategy provides a simple, less expensive way to evaluate gastric emptying in clinical practice with acceptable sensitivity and specificity as an initial test for patients with clinically suspected gastric stasis or dumping syndromes.

Pouchitis--a poorly understood entity

Pouchitis is an increasing drawback to patients who undergo ileal pouch-anal anastomosis for ulcerative colitis; complication overshadows the overall good functional results of this sphincter-saving operation. There is a need for cooperative, multicenter, and longitudinal studies of patients undergoing ileal pouch-anal anastomosis, to unravel the etiology and pathophysiology of pouchitis. Because of the absence of a mucosal inflammation before pouch construction, patients operated on for familial adenomatous polyposis are the perfect control group. Thus, it may be possible to elucidate and define the sequence that leads to pouchitis, including overgrowth of a colonic type flora, transformation of the histology to an epithelium with colonic features, an altered biochemical milieu in the lumen (volatile fatty acids, secondary bile acids), and changes in mucosal defense mechanisms.