Biomedical subjects

B Naliboff

Publications and source records attributed to B Naliboff.

At least 19 recordsLinked to original sources

PubMed2005

Traditional Chinese medicine based subgrouping of irritable bowel syndrome patients.

Partly from lack of effective conventional therapeutics, patients with irritable bowel syndrome (IBS) turn to complementary and alternative approaches, including Traditional Chinese Medicine (TCM). Key to TCM's approach to IBS is individualized therapies targeted at subgroups. Subgroups represent distinct patterns of dysregulation (e.g. "excess" or "deficiency") identified by both intestinal and extra-intestinal symptoms. Our objective was to identify operational criteria supporting the existence of TCM-based subgroups in IBS and to assess reliability and validity of these criteria. Using TCM principles, items were selected on face validity from conventional questionnaires. TCM practitioners evaluated items for content and face validity. Symptom items and a set of patient cases with item responses were validated by examining patient's pattern of response to items and assessing the consistency with which practitioners diagnosed patients on the spectrum of an "excess" or "deficiency" syndrome. Standard correlation analysis revealed 33 intestinal and extra-intestinal symptom items. There was high degree of practitioner agreement in assessing individual items to particular patterns. External validation by practitioners of cases showed high internal consistency among practitioners (Cronbach's alpha coefficients of 0.91 and 0.87 for excess and deficiency, respectively) and high correlation of average practitioner rating to original questionnaire generated scores (Pearson correlation coefficients of 0.94 and 0.92 for excess and deficiency, respectively). This pilot study provides preliminary support for a methodology to identify novel subgroups of IBS patients related to the TCM classification, which may differ in underlying pathophysiology and treatment responses.

Case-Control Studies↗

PubMed2004

Anti-hyperalgesic effect of octreotide in patients with irritable bowel syndrome.

BACKGROUND: Octreotide has been found to be beneficial in the treatment of chronic pain, although the mechanisms underlying its therapeutic effect are incompletely understood. AIMS: To assess the effect of octreotide on perceptual responses to rectal distension in irritable bowel syndrome patients and healthy controls at baseline and following the experimental induction of rectal hyperalgesia. METHODS: In study 1, rectal perception thresholds for discomfort were determined in seven irritable bowel syndrome patients and eight healthy controls on three separate days using a computer-controlled barostat. Subjects received saline, low-dose and high-dose octreotide in a random double-blind fashion. In study 2, perceptual responses to rectal distension were obtained in nine irritable bowel syndrome patients and seven controls before and after repetitive high-pressure mechanical sigmoid stimulation. RESULTS: Octreotide increased the discomfort thresholds in irritable bowel syndrome patients, but not in controls, without changing rectal compliance. Repetitive sigmoid stimulation resulted in decreased rectal discomfort thresholds in the patient group only. In irritable bowel syndrome patients, octreotide prevented the sensitizing effect of repetitive sigmoid stimulation on rectal discomfort thresholds. CONCLUSIONS: Octreotide effectively increased discomfort thresholds in irritable bowel syndrome patients, but not in controls, at baseline and during experimentally induced rectal hyperalgesia. These findings suggest that octreotide exerts primarily an anti-hyperalgesic rather than analgesic effect on visceral perception.

Adult↗

PubMed2001

Involvement of spinal calcitonin gene-related peptide in the development of acute visceral hyperalgesia in the rat.

This study aimed to characterize the role of the neuropeptide calcitonin gene-related peptide (CGRP) in the development of mechanically induced visceral hyperalgesia. Tonic colorectal distension (CRD) was performed in fasted, conscious male Sprague-Dawley rats. The visceromotor reflex associated with noxious CRD was determined as the number of contractions during each of two consecutive tonic distensions (10 min at 60 mmHg), which were separated by a series of phasic distensions (repeated 15-s distensions to 80 mmHg at 30-s intervals). The effect of the CGRP receptor antagonist h-CGRP8-37 given intrathecally (i.t.) (0.03-3 nmol rat-1) or intravenously (i.v.) (20 microg kg-1 bodyweight [bw]) on the visceromotor response was evaluated. The dose for i.v. administration was chosen based on previous results from similar studies. In addition, the effect of a CGRP monoclonal antibody (6 mg kg-1 bw) given intravenously was evaluated. Compared to the baseline response, a significant increase in the number of abdominal contractions was observed during the second tonic distension. The i.t. application of h-CGRP8-37 dose-dependently reduced the numbers of abdominal contractions both during the first and the second tonic distension period, with a maximum effect observed at a peptide concentration of 3 nmol. Intravenous administration of h-CGRP8-37 or of the CGRP antiserum produced a small reduction of the visceromotor response induced by the second tonic distension and had no effect on colonic compliance. The development of mechanically induced colorectal hyperalgesia by repeated tonic distension involves the spinal release of CGRP, while peripheral release of CGRP plays only a minor role.

Acute Disease↗

PubMed2001

Gender-related differences in IBS symptoms.

OBJECTIVE: Women are more likely than men to report irritable bowel syndrome (IBS) symptoms as well as chronic visceral and musculoskeletal pain. The study tests the general hypothesis that female IBS patients differ from their male counterparts in symptoms related to the viscera and musculoskeletal system, and that these differences are related to the menstrual cycle. METHODS: Seven hundred fourteen Rome positive IBS patients were evaluated for GI and extracolonic symptoms, psychological symptoms (SCL-90R), and quality of life (QOL) (SF-36). In addition, 54 postmenopausal women were compared with 61 premenopausal women and 54 age-matched males, all with IBS. RESULTS: Male and female subjects reported similar GI levels of symptom severity and psychological problems. Abdominal distension associated with a sensation of bloating was more commonly reported by female patients, as were symptoms of constipation. Female patients more often reported nausea, alterations of taste and smell, and unpleasant sensations on the tongue, muscle stiffness in the morning, greater food sensitivity, and side effects from medications. Forty percent of female patients reported menstrual cycle-related worsening of symptoms, but few symptom differences were found between pre- and postmenopausal women, making it unlikely that most of the gender differences observed are directly tied to the menstrual cycle. CONCLUSIONS: Female patients report higher levels of a variety of intestinal and nonintestinal sensory symptoms despite similar levels of IBS severity, abdominal pain, psychological symptoms, and illness impact. The apparent differences in sensitivity to nonpainful visceral sensations, medications, and food may represent altered sensory processes, autonomic responses, and/or cognitive hypervigilance.

Abdominal Pain↗

PubMed2001

Sensation of bloating and visible abdominal distension in patients with irritable bowel syndrome.

OBJECTIVES: Abdominal bloating and distension are common symptoms of irritable bowel syndrome (IBS). The postulated pathophysiological mechanisms underlying these symptoms include increased production, retention, or perception of gas or luminal contents. The aims of this study were to prospectively compare the prevalence of, and clinical factors related to, bloating and distension in an IBS patient population. METHODS: A total of 714 consecutive patients who met Rome I criteria for IBS were prospectively surveyed, and were classified as having bloating alone (B) or bloating and distension (B+D) based on a comprehensive bowel symptom questionnaire. GI, extraintestinal, and psychological symptoms, as well as health-related quality of life measures were also assessed using validated survey instruments. RESULTS: A total of 542 IBS patients (76%) who reported abdominal bloating were studied. Of these, 132 patients fulfilled criteria for the B group, whereas 410 patients fulfilled criteria for the B+D group. There was a significantly different gender distribution in the B and B+D groups (female:male ratios, 1.4:1 and 2.8:1, respectively p < 0.02). There was also a significantly different bowel habit subgroup distribution, with a greater predominance of constipation in B+D group and of diarrhea in the B group (p < 0.03). Both groups were similar in other clinical parameters, including progressive worsening of symptoms during the day, and relief by passing stool or gas. Both bloating and distension worsened when other abdominal symptoms worsened. Abdominal distension was associated with greater symptom severity and less diurnal variation in symptoms, and was less often perceived as associated with food intake. CONCLUSIONS: Bloating and visible abdominal distension may arise from two distinct but interrelated physiological processes. Although the sensation of bloating may be related to enhanced sensitivity to visceral afferent stimulation, abdominal distension in more severely affected patients may be related to triggering of a visceromotor reflex affecting the tone of abdominal wall muscles.

Abdomen↗

PubMed2000

The evolving neurobiology of gut feelings.

The bi-directional communication between limbic regions and the viscera play a central role in the generation and expression of emotional responses and associated emotional feelings. The response of different viscera to distinct, emotion-specific patterns of autonomic output is fed back to the brain, in particular to the cingulofrontal convergence region. Even though this process unfolds largely without conscious awareness, it plays an important role in emotional function and may influence rational decision making in the healthy individual. Alterations in this bi-directional process such as peripheral pathologies within the gut or alterations at the brain level may explain the close association between certain affective disorders and functional visceral syndromes.

Animals↗

PubMed2000

Differences in somatic perception in female patients with irritable bowel syndrome with and without fibromyalgia.

BACKGROUND: Irritable bowel syndrome (IBS) and fibromyalgia (FM) are considered chronic syndromes of altered visceral and somatic perception, respectively. Because there is a significant overlap of IBS and FM, shared pathophysiological mechanisms have been suggested. Although visceral perception has been well studied in IBS, somatic perception has not. AIMS: To compare hypervigilance and altered sensory perception in response to somatic stimuli in patients with IBS, IBS+FM, and healthy controls. METHODS: Eleven IBS females (mean age 40), 11 IBS+FM females (mean age 46), and ten healthy female controls (mean age 39) rated pain perception in response to pressure stimuli administered to active somatic tender points, non-tender control points and the T-12 dermatome, delivered in a predictable ascending series, and delivered in an unpredictable randomized fashion (fixed stimulus). RESULTS: Although IBS patients had similar pain thresholds during the ascending series compared with controls, they were found to have somatic hypoalgesia with higher pain thresholds and lower pain frequency and severity during fixed stimulus series compared with IBS+FM patients and controls (P<0.05). Patients with IBS+FM were more bothered by the somatic stimuli and had somatic hyperalgesia with lower pain thresholds and higher pain frequency and severity. CONCLUSIONS: Both hypervigilance and somatic hypoalgesia contribute to the altered somatic perception in IBS patients. Co-morbidity with FM results in somatic hyperalgesia in IBS patients.

Adult↗

PubMed2000

The impact of irritable bowel syndrome on health-related quality of life.

BACKGROUND & AIMS: Few data are available to evaluate health-related quality of life (HRQOL) of people with irritable bowel syndrome (IBS). We evaluated and compared the impact of IBS on HRQOL using previously reported HRQOL data for the U.S. general population and for people with selected chronic diseases. METHODS: Using the SF-36 Health Survey, we compared the HRQOL of IBS patients (n = 877) with previously reported SF-36 data for the general U.S. population and for patients with gastroesophageal reflux disease (GERD), diabetes mellitus, depression, and dialysis-dependent end-stage renal disease (ESRD). RESULTS: On all 8 SF-36 scales, IBS patients had significantly worse HRQOL than the U.S. general population (P < 0. 001). Compared with GERD patients, IBS patients scored significantly lower on all SF-36 scales (P < 0.001) except physical functioning. Similarly, IBS patients had significantly worse HRQOL on selected SF-36 scales than patients with diabetes mellitus and ESRD. IBS patients had significantly better mental health SF-36 scale scores than patients with depression (P < 0.001). CONCLUSIONS: IBS patients experience significant impairment in HRQOL. Decrements in HRQOL are most pronounced in energy/fatigue, role limitations caused by physical health problems, bodily pain, and general health perceptions. These data offer further insight into the impact of IBS on patient functional status and well-being.

Adult↗

PubMed2000

Correlation of symptom criteria with perception thresholds during rectosigmoid distension in irritable bowel syndrome patients.

OBJECTIVE: Due to a lack of reliable biological markers, the diagnosis of irritable bowel syndrome (IBS) is based on symptom criteria. The possible physiological correlates of these criteria are not known. Our aims were to identify correlations of currently used IBS symptom criteria with distinct alterations in visceral perception. METHODS: Forty-two IBS patients (51% women) with a mean age of 39.5+/-1.4 yr, were included; 64% of patients were recruited from advertisement and 36% were clinic referrals. Patients completed a bowel symptom questionnaire, which included the Rome criteria and symptom severity ratings. Rectal discomfort thresholds were evaluated in all patients and in 19 controls, using a nonbiased tracking protocol consisting of phasic rectal balloon distensions before (PreTh) and after (PostTh) repetitive, high-pressure sigmoid distensions. We assessed the effect of each Rome criteria and symptom severity on PreTh and PostTh. RESULTS: IBS symptom severity was reported as moderate in 38.1% and as severe in 61.9% of patients. Overall, lower thresholds were observed in IBS patients than in controls (PreTh: 28.2+/-1.7 vs. 36.3+/-2.8 mm Hg, p<0.05; PostTh: 25.3+/-1.5 vs. 34.2+/-2.7 mm Hg, p<0.01). When assessing the effect of Rome criteria on rectal thresholds, we found that patients with hard/lumpy stools had lower thresholds than those without them, whereas patients with loose watery stools had higher thresholds than those who lacked them (both p<0.05). The lowering of rectal discomfort thresholds after sigmoid stimulation was observed regardless of the presence or absence of any Rome criteria or symptom severity. CONCLUSION: Although a decrease in rectal discomfort thresholds after sigmoid stimulation is seen in IBS regardless of specific symptoms, baseline and postsigmoid stimulation thresholds are lower in IBS patients with constipation-related symptoms.

Adult↗

PubMed2000

Perceptual responses in patients with inflammatory and functional bowel disease.

BACKGROUND AND AIMS: Enhanced visceral sensitivity following a transient inflammatory process in the gut has been postulated as an aetiological mechanism of irritable bowel syndrome (IBS). In this study we compared perceptual responses to rectosigmoid distension in patients with mild chronic inflammation of the rectum (ulcerative colitis (UC)) and patients without mucosal inflammation (IBS) to determine if chronic low grade mucosal inflammation may be a plausible explanation for rectosigmoid hypersensitivity reported in both IBS and UC patients. METHODS: UC disease activity was quantified using activity index scores. Perception thresholds for discomfort during rectosigmoid distension were compared between 11 UC patients with quiescent or mild disease activity, 18 IBS patients, and 13 healthy controls. RESULTS: Although UC activity index scores negatively correlated with perceptual thresholds for discomfort (r=-0.76, p=0.016), UC patients had higher discomfort thresholds compared with IBS patients and controls before (p=0.02) and after (p<0.001) a noxious sigmoid conditioning stimulus. CONCLUSIONS: Rectal perception was attenuated in UC but enhanced in IBS. In chronic mild inflammation, activation of antinociceptive mechanisms may prevent the development of visceral hyperalgesia. Low grade mucosal inflammation alone is unlikely to be responsible for symptoms in functional gastrointestinal disorders.

Adult↗

PubMed1999

Review article: gender-related differences in functional gastrointestinal disorders.

Many functional gastrointestinal disorders and other chronic visceral pain disorders such as interstitial cystitis and chronic pelvic pain are more common in women than in men. In irritable bowel syndrome (IBS) there is a 2:1 female to male ratio in prevalence of symptoms in community samples. Female irritable bowel syndrome patients are more likely to be constipated, complain of abdominal distension and of certain extracolonic symptoms. While animal studies have clearly demonstrated gender-related differences in pain perception and antinociceptive mechanisms, unequivocal evidence for gender-related differences in human pain perception or modulation has only been provided recently. Gender-related differences may be related to constant differences in the physiology of pain perception, such as structural or functional differences in the visceral afferent pathways involved in pain transmission or modulation, and/or they may be related to fluctuations in female sex hormones. Preliminary evidence suggests that female irritable bowel syndrome patients show specific perceptual alterations in regards to rectosigmoid balloon distension and that they show differences in regional brain activation measured by positron emission tomography. This preliminary evidence suggests that gender-related differences in symptoms and in the perceptual responses to visceral stimuli exist in IBS patients and can be detected using specific stimulation paradigms and neuroimaging techniques.

Animals↗

PubMed1999

Impact of advertisement and clinic populations in symptoms and perception of irritable bowel syndrome.

BACKGROUND: This study assessed the impact of recruitment on irritable bowel syndrome clinical trials, by determining whether irritable bowel syndrome patients recruited from advertisement or a specialty clinic differ in clinical and physiologic measures. METHODS: We prospectively surveyed 657 irritable bowel syndrome patients who either: (i) were referred from a functional bowel disease clinic (52%); or (ii) responded to advertisement for clinical trials (48%), using questionnaires about bowel and psychological symptoms, and quality of life. In a subset of 42 irritable bowel syndrome patients (29 advertisement and 15 clinic patients), rectal discomfort thresholds were measured before and after repetitive sigmoid stimulation. RESULTS: While the advertisement population more commonly consulted primary care physicians, the clinic population more commonly consulted gastroenterologists. The clinic population reported more prevalent and severe abdominal pain, and higher psychological symptom scores, while the advertisement population had greater quality of life. In the visceral perception studies, both subgroups were hypersensitive to rectal distension. CONCLUSION: Compared to the clinic population, the advertisement population had less severe abdominal pain and psychological symptoms, better quality of life but similar visceral perception. The differences in clinical self-reports may have consequences for enrolment of these different patient populations into clinical trials.

Adult↗

PubMed1999

Symptoms and physiology in severe chronic constipation.

OBJECTIVE: Symptoms of constipation have been attributed to slow colon transit, irritable bowel syndrome (IBS), or pelvic floor dysfunction (PFD). Our aim was to determine the existence of symptom-based constipation subgroups and whether these correspond to differences in colonic transit and anorectal sensorimotor function. METHODS: Constipated patients (n = 108) completed questionnaires, and underwent colon transit studies, anorectal manometry, and rectal sensory testing. Factor analysis of symptoms was performed. Factor-based symptom scores were correlated with physiological findings. RESULTS: Three symptom factors were identified as compatible with slow colonic transit, IBS, and PFD. There was a significant correlation between the symptoms of slow transit and total and rectosigmoid colon transit. There were also significant correlations between both the IBS symptom score and the number of Manning criteria with measures of rectal hypersensitivity typical of IBS. Neither PFD symptom scores nor symptoms of straining correlated with any electromyographic or manometric measure of anal defecatory function or with rectosigmoid colon transit. Based on physiological testing patients were classified as slow transit, visceral hypersensitivity (typical of IBS), PFD, or no abnormalities found. As expected, slow-transit patients had symptoms of infrequent stools and patients with visceral hypersensitivity had an increased number of Manning criteria for IBS. Patients with PFD physiology and those with no detectable abnormalities had no specific symptoms. CONCLUSIONS: Three symptom-based subgroups for constipation were confirmed: slow transit, IBS, and PFD. Slow transit and IBS symptoms correlated with expected physiology. Conversely, PFD symptoms and physiology did not correlate.

Anal Canal↗

PubMed1999

Symptoms and visceral perception in patients with pain-predominant irritable bowel syndrome.

OBJECTIVE: Abdominal pain is thought to be a hallmark of the irritable bowel syndrome (IBS), although currently used symptom criteria do not differentiate between abdominal pain and discomfort. By focusing on viscerosensory symptoms, we sought to determine: 1) which type of symptoms are most commonly reported by IBS patients, and 2) whether patients who report pain as their most bothersome symptom differ in clinical, psychological, and physiological characteristics. METHODS: A total of 443 consecutive new patient referrals to a tertiary referral center for functional gastrointestinal disorders who met symptom criteria for IBS were given validated, psychometric, health status, and bowel symptom questionnaires containing specific questions regarding the patients' predominant viscerosensory gastrointestinal symptom. Of these patients, 155 (35%) also met criteria for functional dyspepsia. A representative subset of the total IBS patient population (n = 58) underwent evaluation of perceptual responses to controlled rectal distension before and after a noxious sigmoid conditioning stimulus. RESULTS: Viscerosensory symptoms clustered into four groups: 1) abdominal pain, 2) bloating-type discomfort, 3) sensation of incomplete rectal evacuation, and 4) extraabdominal (chest pain or pressure and nausea). A total of 66% of patients reported gas as one of their viscerosensory symptoms, whereas 60% reported abdominal pain as one of their symptoms. Only 29% rated abdominal pain as their most bothersome symptom, whereas bloating-type symptoms were listed by 60% as most bothersome. Although pain predominance did not correlate with the severity of gastrointestinal or psychological symptoms, there was a significant correlation with the development of rectal hypersensitivity in response to the sigmoid conditioning stimulus. CONCLUSIONS: In a tertiary referral population of IBS patients: 1) abdominal pain is reported by only one third of patients as their most bothersome viscerosensory symptoms; and 2) pain-predominance correlates with development of rectal hypersensitivity after a noxious sigmoid stimulus.

Abdominal Pain↗

PubMed1999

Symptom differences in moderate to severe IBS patients based on predominant bowel habit.

OBJECTIVE: We sought to determine if irritable bowel syndrome (IBS) patients with different bowel habit predominance differ in self-reported viscerosensory symptoms related to the upper and lower gastrointestinal (GI) tract, somatosensory symptoms, and constitutional functions. METHODS: Six hundred and twenty-five Rome criteria-positive IBS patients completed a bowel symptom questionnaire (BSQ), psychological symptom checklist (SCL-90), and health status (SF-36). Bowel habit predominance for IBS patients was determined using the Rome criteria for functional constipation (IBS-C; n = 140) and functional diarrhea (IBS-D; n = 216). The BSQ included questions about viscerosensory symptoms of the upper (chest pressure, bloating, fullness, early satiety, nausea) and lower GI tract (bloating, pain, incomplete evacuation), somatosensory symptoms related to the musculoskeletal system (pain in neck/shoulders, lower back/hip, muscles/joints), and constitutional functions (sleep, appetite, libido). Analysis was further conducted between the IBS-C and IBS-D patients, controlling for gender and quality of sleep, and using the Bonferroni correction to control for multiple comparisons. RESULTS: Female gender was more prevalent among IBS-C than IBS-D (77% vs 56.1%, p < 0.01), whereas age did not differ (40.2 +/- 1.2 yr vs 39.5 +/- 1.0 yr). Symptoms referred to the upper GI were more prevalent in IBS-C than IBS-D: early satiety (56.7% vs 33.9%, p < 0.004), fullness (63.2% vs 38.5%, p < 0.05), and a trend for upper bloating (80.3 vs 62.6%). IBS-C patients reported higher severity ratings for lower GI bloating (p < 0.001). IBS-C more commonly reported musculoskeletal symptoms (92.2% vs 75.4%, p < 0.001), as well as impairment in sleep (31.3 vs 17.5%, p < 0.009), appetite (35.0% vs 18.4%, p < 0.015) and sexual function (45.2% vs 33.1%, p < 0.0021). There were no differences in SCL-90 and SF-36 scores. CONCLUSIONS: Compared with the IBS-D group, the IBS-C patients show greater prevalence of a wide range of symptoms referred to the upper and lower abdomen, musculoskeletal, and constitutional functions. These findings may be related to differences in autonomic or perceptual responses to visceral and somatic stimuli, and are likely to have implications for treatment responses in the two subgroups.

Adult↗

PubMed1999

Physiology of refractory chronic constipation.

OBJECTIVE: Investigators suggest three distinct pathophysiologies for patients with constipation symptoms: 1) slow colon transit, 2) irritable bowel syndrome (IBS), and 3) pelvic floor dysfunction (PFD). Our aim was to determine the prevalence of the three types of constipation pathophysiology, the degree of overlap, and what interactions exist between pathophysiologies. METHODS: Constipated patients refractory to fiber (n = 131) underwent regional colon transit studies, anorectal manometry/EMG, measurement of rectal compliance, and rectal sensory testing. Correlations were performed examining interactions between the above measures. RESULTS: Visceral hypersensitivity (typical of IBS) was found in 58%, slow colonic transit in 47%, PFD in 59%, and no physiological abnormalities were detected in 24%. Slow transit and visceral hypersensitivity overlapped in half of each group. PFD physiology was found in approximately half of each of the subgroups. There was no correlation between PFD physiology and rectosigmoid transit, total colon transit, or any other physiology. There were no correlations between slow transit and visceral hypersensitivity. Visceral hypersensitivity did correlate with increased rectal compliance, suggestive of increased accommodation reflexes in IBS. CONCLUSIONS: At a tertiary center, slow transit physiology and visceral hypersensitivity typical of IBS are equally common and overlap heavily in constipated patients. PFD physiology does not correlate with slower rectosigmoid colon transit, and is seen equally in all subgroups. No abnormalities were found in 24% of patients. We therefore identify four subgroups in constipation: IBS, slow transit, both, and neither.

Chronic Disease↗

PubMed1998

Differential effect of long-term esophageal acid exposure on mechanosensitivity and chemosensitivity in humans.

BACKGROUND & AIMS: Chronic tissue injury in the esophagus associated with gastroesophageal reflux disease may result in sensitization of afferent pathways mediating mechanosensitivity and chemosensitivity. The aim of this study was to evaluate the sensitivity to intraluminal acid and to distention of the esophagus in patients with mild-to-moderate gastroesophageal reflux disease. METHODS: Perceptual responses to intraluminal acid perfusion and to esophageal distention and pressure volume relationships were evaluated in 10 healthy volunteers and in 11 patients. Mechanosensitivity was evaluated with a barostat using unbiased distention protocols and verbal descriptor ratings of sensations. Chemosensitivity to acid was determined at baseline and after a 1-month treatment of acid suppression. RESULTS: Patients showed enhanced perception of acid perfusion but not of esophageal distension. Chemosensitivity but not mechanosensitivity was correlated with reflux symptoms and with the degree of endoscopically shown tissue injury at baseline. Tissue injury was not associated with altered compliance. CONCLUSIONS: Mild-to-moderate chronic tissue injury in gastroesophageal reflux disease differentially affects mechanosensitive and chemosensitive afferent pathways. Chronic acid reflux by itself is not likely to play a role in reported esophageal hypersensitivity to distention in patients with noncardiac chest pain.

Adult↗

PubMed1998

Symptoms and visceral perception in severe functional and organic dyspepsia.

BACKGROUND: Hypersensitivity of gastric afferent pathways may play an aetiological role in symptoms of functional dyspepsia. AIMS: To determine whether patients with severe organic dyspepsia (associated with tissue irritation/injury) and those with functional dyspepsia (no detectable tissue irritation) differ in their perception of gastric distension and whether this difference is reflected in differences in their gastrointestinal and psychological symptoms. METHODS: Perceptual thresholds, referral patterns, and gastrointestinal and psychological symptoms were compared in 23 patients with functional dyspepsia, 10 organic dyspeptics, and 15 healthy controls. RESULTS: Fifteen (65%) functional dyspeptics and no organic dyspeptics had reduced perceptual thresholds for fullness, discomfort, or pain (odds ratio (OR) 19.56, 95% confidence interval (CI) 1.95 to 476.09, p = 0.0017). Either reduced perceptual thresholds or altered referral was found in 20 (87%) functional dyspeptics and four (20%) organic dyspeptics (OR 10.0, 95% CI 1.34 to 89.54, p = 0.014). During sham distension fullness, discomfort and pain were reported by healthy controls, organic dyspeptics, and functional dyspeptics. A sham response of pain but no other sensation was more frequent among functional dyspeptics (43%) than healthy controls (7%) (OR 10.77, 95% CI 1.10 to 257.35, p = 0.026). Gastrointestinal and psychological symptoms and gastric compliance were similar in the functional and organic groups. CONCLUSIONS: Alterations in the perception of gastric distension distinguishes between functional and organic dyspepsia, while symptoms do not. A total of 87% of functional dyspeptics studied had evidence of altered visceral afferent function. In this study population, psychological abnormalities or changes in compliance did not explain the findings.

Adult↗