Sympathetic (electrodermal) activity during repeated maximal rectal distensions in patients with irritable bowel syndrome and constipation

Abstract  Irritable bowel syndrome (IBS) is associated with visceral hypersensitivity, stress and autonomic dysfunction. Sympathetic activity during repeated events indicates excitatory or inhibitory mechanisms such as sensitization or habituation. We investigated skin conductance (SC) during repetitive rectal distensions at maximal tolerable pressure in patients with IBS and chronic constipation. Twenty-seven IBS patients, 13 constipation patients and 18 controls underwent two sets of isobaric rectal distensions. First, maximal tolerable distension was determined and then it was repeated five times. Skin conductance was measured continuously. Subjective symptom assessment remained steady in all groups. The baseline values of SC were higher in IBS patients than in patients with constipation and significantly lower in constipation patients than in controls. The maximal SC response to repetitive maximal distensions was higher in IBS patients compared with constipation patients. The amplitude of the initial SC response decreased successively with increased number of distensions in patients with IBS and constipation but not in controls. Irritable bowel syndrome and constipation patients habituated to maximal repetitive rectal distensions with decreasing sympathetic activity. Irritable bowel syndrome patients had higher sympathetic reactivity and baseline activity than constipation patients. A lower basal SC in constipation patients compared with controls suggests an inhibition of the sympathetic drive in constipation patients.     

Catecholamine and cortisol levels during sleep in women with irritable bowel syndrome

Abstract  Evidence suggests that patients with irritable bowel syndrome (IBS) are hyper-responsive to environmental, physical and visceral stimuli. IBS patients also frequently report poor sleep quality. This study compared serum cortisol and plasma catecholamine levels during sleep between women with IBS ( n  = 30) and healthy controls ( n  = 31), and among subgroups within the IBS sample based on predominant stool patterns, IBS-diarrhoea ( n  = 14), IBS-constipation ( n  = 7) and IBS-alternators ( n  = 9). Cortisol was measured from serial blood samples drawn every 20 min, and catecholamines every hour, in a sleep laboratory from 8  pm until awakening. Because of the varied sleep schedules of the individual participants, each subject's hormone series time base was referenced with respect to their onset of Stage 2 sleep. Overall, there were no significant differences in cortisol or catecholamine patterns between women with IBS and controls, nor were there any group by time interactions. However, women with constipation-predominant IBS demonstrated significantly increased noradrenaline, adrenaline and cortisol levels throughout the sleep interval, and women with diarrhoea-predominant IBS were significantly lower on noradrenaline and cortisol. These results suggest that differences in neuroendocrine levels during sleep among IBS predominant bowel pattern subgroups may be greater than differences between IBS women and controls. Neuroendocrine profiles during sleep may contribute to our understanding of symptom expression in IBS.     

Perceptual sensitivity and response bias during rectal distension in patients with irritable bowel syndrome.

Patients with irritable bowel syndrome (IBS) report an increased frequency of sensations during rectal distension in comparison with healthy subjects. This alteration might be due to a psychological response bias leading patients to over report their sensations. The aim of this study was to measure perceptual sensitivity and response bias during rectal distension in healthy subjects and IBS patients using the sensory decision theory (SDT). Thirteen healthy subjects and 22 IBS patients underwent five rectal distensions up to 100 mL, five up to 200 mL and five sham distensions. They were asked to identify the distension by means of an electronic marker. Perceptual sensitivity and response bias were calculated according to the SDT. The patients identified a more 100 mL distensions than the healthy subjects (P = 0.02), whereas there was no difference in the number of identified 200 mL and sham distensions between the two groups. The perceptual sensitivity of IBS patients was significantly greater during 100 mL (P = 0.01), but not during 200 mL distensions. The response bias was not significantly different between the two groups. These data suggest that the increased frequency of sensations reported by IBS patients is not due to a psychological response bias.     

Abnormal rectal motor physiology in patients with irritable bowel syndrome

A contentious issue is whether irritable bowel syndrome (IBS) patients have abnormal rectal motor physiology. Our aim was to determine whether IBS patients have abnormal rectal responses to low (urge producing) or high (pain producing) distension pressures. The IBS patients and healthy controls underwent five series of isobaric rectal distensions to examine volume-pressure relationships and rectal accommodation: (i) ascending stepwise distensions terminating upon report of moderate pain, (ii) phasic and (iii) tonic distensions at a single low pressure producing a moderate sensation of urge to defecate (iv) phasic and (v) tonic distensions at a single high pressure producing a moderate pain sensation. The IBS patients demonstrated a lower rectal volume-pressure ratio during repetitive single-pressure phasic distensions, and a slower rate of rectal accommodation during low (but not high) pressure tonic distensions. However, dynamic compliance during ascending stepwise distensions and the change in rectal volume during tonic distension were not significantly different from controls. Rectal abnormality was readily demonstrated by determining the volume-pressure ratio using a small number of repetitive single-pressure distensions, supporting the hypothesis that IBS patients have abnormal rectal motor physiology. We propose that a peripheral neuromuscular substrate may contribute to the pathogenesis of IBS.     

Small intestinal bacterial overgrowth in irritable bowel syndrome: association with colon motility, bowel symptoms, and psychological distress

Abstract  Small intestinal bacterial overgrowth (SIBO) has been implicated in the pathogenesis of irritable bowel syndrome (IBS), although the issue is still under debate. The aim of this study was to determine the prevalence of SIBO in those with IBS and its association with colonic motility, bowel symptoms and psychological distress. Sucrose hydrogen and methane breath tests were performed in 158 IBS patients and 34 healthy controls (HC). Thresholds for pain and urgency were tested by barostat in the descending colon. The motility index (MI) was calculated as the average area under the curve for all phasic contractions. Questionnaires assessed psychological distress, IBS symptom severity (IBS-SS), IBS quality of life (IBS-QOL) and self-reported bowel symptoms. Fifty-two of 158 (32.9%) IBS patients had abnormal breath tests compared with six of 34 (17.9%) HC (χ² = 0.079). SIBO (SIBO+) and non-SIBO (SIBO−) patients did not differ in the prevalence of IBS subtypes, IBS-SS, IBS-QOL and psychological distress variables. IBS patients had a greater post-distension increase in MI than HC, but there was no difference between SIBO+ and SIBO− patients. Predominant methane producers had higher urge thresholds (28.4 vs 18.3, P  < 0.05) and higher baseline MI (461 vs 301.45, P  < 0.05) than SIBO− IBS patients, and they reported more 'hard or lumpy stools' when compared with predominant hydrogen producers ( P  < 0.05) and SIBO− IBS patients ( P  < 0.05). SIBO is unlikely to contribute significantly to the pathogenesis of IBS. Methane production is associated with constipation.     

Distension technique influences the relationship between colonic and rectal hypersensitivity in irritable bowel syndrome

In irritable bowel syndrome (IBS), it remains unclear whether rectal hypersensitivity is a 'marker' of colonic hypersensitivity. Our aim was to examine the relation between colonic and rectal sensitivity in IBS patients, comprising phasic and ramp distension techniques. Twenty IBS patients and 12 healthy subjects (N) underwent stepwise ramp and random phasic barostat distensions in the colon and rectum in random order. The sensory threshold pressure (ramp distension) and the visual analogue scale score (VAS, phasic distension), for pain and non-pain, were recorded. Colonic thresholds were lower, and VAS scores were generally higher, for pain and non-pain sensitivities in IBS compared to N. Rectal thresholds were lower, and VAS scores were higher, for pain but not for non-pain, in IBS compared to N. In IBS, for phasic distension, there was good correlation between the colon and rectum for non-pain (e.g. at 16 mmHg, r=0.59, P=0.006) and pain (r=0.60, P=0.006) sensitivities. In contrast, there was no significant correlation between the colon and rectum for ramp distension. In conclusion, colonic and rectal sensitivity in IBS are correlated in response to phasic but not ramp barostat distensions. The rectum serves as a legitimate 'window' for evaluating colonic hypersensitivity in IBS, provided that phasic distensions are employed.     

Enteroendocrine cell counts correlate with visceral hypersensitivity in patients with diarrhoea-predominant irritable bowel syndrome

The objective of this study was to determine whether or not the number of enteroendocrine cells (ECs) in the gut is related to visceral hypersensitivity in patients with diarrhoea-predominant irritable bowel syndrome (D-IBS). Twenty-five subjects with D-IBS (mean, 43.1 years; 16 women, nine men) were recruited into our study, along with 13 healthy controls (mean, 40.7 years; nine women, four men). Maximally tolerable pressures were evaluated via barostat testing, and the levels of ECs were immunohistochemically identified and quantified via image analysis. The numbers of ECs between the D-IBS subjects and the controls were not significantly different in the terminal ileum, ascending colon and rectum. However, the maximally tolerable pressures determined in the D-IBS subjects were significantly lower than those of the control subjects (P < 0.01), and we detected a significant relationship between the maximally tolerable pressures and the numbers of ECs in the rectum (r = -0.37, P < 0.01). Rectal sensitivity was enhanced to a greater degree in D-IBS patients exhibiting an elevated level of rectal ECs. This study provides some evidence to suggest that ECs play an important role in visceral hypersensitivity.     

Subjective theories of illness and clinical and psychological outcomes in patients with irritable bowel syndrome

Objectives

Patients' ideas about the nature, cause, and treatment of their illnesses are part of the complex process of coping with illness. To date, limited research on subjective theories of illness in patients with irritable bowel syndrome (IBS) has been performed. The aim of the study was to investigate patients' subjective theories of illness and how these are related to clinical and psychological outcome criteria, in particular IBS symptom severity and quality of life.

Methods

Eighty-eight patients with IBS, as defined by Rome III criteria, were administered a battery of questionnaires to collect the following data: sociodemographic variables, subjective theories of illness (Subjektive Krankheitstheorien, Cause Questionnaire), anxiety (Hospital Anxiety and Depression Scale), depression (Beck Depression Inventory), quality of life (SF-12), and IBS symptoms (Questionnaire for Gastrointestinal Symptoms).

Results

Almost all patients reported theories of illness reflecting their subjective causal assumptions. The most frequently mentioned causal factors were physical illness, intrapsychic factors, and stress.Patients with mainly somatic attributions had higher IBS symptoms scores (P<.05) and reduced physical quality of life. Intrapsychic attributions were associated with reduced mental quality of life and enhanced physical quality of life (P<.01). All correlations were independent of gender, age, and irritable bowel subgroups.

Conclusions

Subjective theories of illness can have significant implications for IBS symptom severity, as well as for physical and mental quality of life.     

Options for patients with irritable bowel syndrome: contrasting traditional and novel serotonergic therapies

This article reviews the efficacy and tolerability of traditional therapies for irritable bowel syndrome (IBS) and concludes that they are limited by both poor efficacy and adverse effects. Serotonin, a neurotransmitter found mainly in the gut, appears to represent a link in IBS pathophysiological processes -- altered gut motility, abnormal intestinal secretion and visceral hypersensitivity. Recently, available treatments for IBS have targeted serotonin receptors that are involved in motor, sensory and secretory functions of the gut. Serotonergic agents, such as alosetron (a 5-HT3 receptor antagonist) and tegaserod (a selective 5-HT4 receptor partial agonist), provide global relief of the multiple symptoms of IBS with diarrhoea and IBS with constipation, respectively, and represent important additions to the IBS treatment armamentarium.     

Increase in fecal primary bile acids and dysbiosis in patients with diarrhea-predominant irritable bowel syndrome

Background Irritable bowel syndrome (IBS) is a multifactorial disease for which a dysbiosis of the gut microbiota has been described. Bile acids (BA) could play a role as they are endogenous laxatives and are metabolized by gut microbiota. We compared fecal BA profiles and microbiota in healthy subjects (HS) and patients with diarrhea‐predominant IBS (IBS‐D), and we searched for an association with symptoms. Methods Clinical features and stool samples were collected in IBS‐D patients and HS. Fecal BA profiles were generated using HPLC coupled to tandem mass spectrometry. The fecal microbiota composition was assessed by q‐PCR targeting dominant bacterial groups and species implicated in BA transformation. Key Results Fourteen IBS‐D patients and 18 HS were included. The two groups were comparable in terms of age and sex. The percentage of fecal primary BA was significantly higher in IBS‐D patients than in HS, and it was significantly correlated with stool consistency and frequency. Fecal counts of all bacteria, lactobacillus, coccoides, leptum and Faecalibacterium prausnitzii were similar. There was a significant increase of Escherichia coli and a significant decrease of leptum and bifidobacterium in IBS‐D patients. Conclusions & Inferences We report an increase of primary BA in the feces of IBS‐D patients compared to HS, correlated with stool consistency and frequency. A dysbiosis of different bacterial groups was detected, some of them involved in BA transformation. As the gut microbiota is the exclusive pathway to transform primary into secondary BA, this suggests a functional consequence of dysbiosis, leading to lower BA transformation.     

Associations of tryptophan hydroxylase gene polymorphisms with irritable bowel syndrome

Background Alterations in serotonin (5‐HT) are suspected in the pathophysiology of irritable bowel syndrome (IBS). Tryptophan hydroxylase (TPH) is the rate‐limiting enzyme in the biosynthesis of serotonin and has two isoforms: TPH1 and TPH2. Genetic variants in both genes have been studied in various disorders related to serotonin dysregulation. The aim of this study was to examine whether TPH gene variants were associated with IBS and IBS‐related gastrointestinal (GI) symptoms. Methods Five single nucleotide polymorphisms (SNPs) from the TPH1 and one SNP from the TPH2 were genotyped in 199 IBS patients and 79 healthy controls. All subjects were Caucasian women of European origin. Irritable bowel syndrome patients filled in a daily diary with five GI symptoms and stool characteristics for 28 days. Key Results The TPH1 SNPs showed no association with the diagnosis of IBS. However, among IBS patients, all five TPH1 SNPs showed some association with diarrhea and loose type of stool consistency, with P‐values rating from 0.01 to 0.20. The TPH2 SNP showed a trend towards a reduced risk of IBS and possible associations with stool characteristics, both hard and loose stools. However, no P‐values were less than the conservative multiple‐comparison‐adjusted threshold of 0.001 and hence these results must be interpreted cautiously. Conclusions & Inferences This study is the first to assess associations of TPH gene variants with IBS‐related GI symptoms and stool characteristics. The possible association of TPH gene variants with diarrhea needs to be verified in an independent sample.     

Sensory signalling effects of tegaserod in patients with irritable bowel syndrome with constipation.

Tegaserod relieves overall and multiple individual constipation-predominant irritable bowel syndrome (IBS-C) symptoms. However, mechanisms for the relief of abdominal pain/discomfort are not well understood. The effects of tegaserod on rectal sensitivity to distension were measured by the nociceptive flexion RIII reflex, as evidenced by spinal hyperexcitability (i.e. increase or facilitation of the RIII reflex), in IBS-C patients. A randomized, double-blind, placebo-controlled, parallel study was performed in 30 women with IBS-C. The effects of slow ramp rectal distension on the RIII reflex, recorded from the lower limb, were measured before [first experimental day (D1)] and after 7 days [day 8 (D8)] of placebo (n=15) or 6 mg tegaserod bid (n=15). Pressure-volume and sensation-volume relationships were measured during distension, and patients reported their IBS symptoms daily. On D1, rectal distension facilitated the RIII reflex in both treatment groups. On D8 vs D1 these facilitatory effects were significantly lower (P<0.001, analysis of variance) after tegaserod (mean reduction: -30.3+/-11.9%) than placebo (mean reduction: -10.1+/-12.9%). No significant changes in the volume-sensation relationship or differences in compliance were observed with tegaserod or placebo. In conclusion, tegaserod reduces the facilitatory effects of rectal distension on the RIII reflex in women with IBS-C.     

Anticipation of public speaking and sleep and the hypothalamic-pituitary-adrenal axis in women with irritable bowel syndrome

Background Evidence suggests that subgroups of patients with irritable bowel syndrome (IBS) are hyper‐responsive to a variety of laboratory stress conditions. Methods This study compared sleep quality and night time plasma adrenocorticotropic hormone (ACTH) and serum cortisol levels in response to anticipation of public speaking between 43 women with IBS and 24 healthy control women. In addition, comparisons were made between subgroups within the IBS sample based on predominant stool patterns, 22 IBS‐constipation and 21 IBS‐diarrhea. Subjects slept three nights in a sleep laboratory, and on the third night serial blood samples were drawn every 20 min from 08:00 PM until awakening. As the subjects had different sleep onsets, each subject’s results were synchronized to the first onset of stage 2 sleep. Key Results Compared the healthy control group, women with IBS had significantly worse sleep efficiency, and higher cortisol but not ACTH levels over the night. However, there were no IBS bowel pattern subgroup differences. Among IBS subjects, cortisol levels early in the night were higher than found in our previous study with a similar protocol but without the threat of public speaking. These results suggest that a social stressor, such as public speaking prior to bedtime, increases cortisol but not ACTH levels suggesting HPA dysregulation in women with IBS. Conclusions & Inferences This response to a social stressor contributes to our understanding of the relationship of stress to symptom expression in IBS.     

Hypnotherapy for irritable bowel syndrome: the response of colonic and noncolonic symptoms

There is now good evidence that hypnotherapy benefits a substantial proportion of patients with irritable bowel syndrome and that improvement is maintained for many years. Most patients seen in secondary care with this condition also suffer from a wide range of noncolonic symptoms such as backache and lethargy, as well as a number of musculoskeletal, urological, and gynaecological problems. These features do not typically respond well to conventional medical treatment approaches, but fortunately, their intensity is often reduced by hypnosis. The mechanisms by which hypnosis mediates its benefit are not entirely clear, but there is evidence that, in addition to its psychological effects, it can modulate gastrointestinal physiology, alter the central processing of noxious stimuli, and even influence immune function.     

Hypervigilance in irritable bowel syndrome compared with organic gastrointestinal disease

Objective

Irritable bowel syndrome (IBS) patients are suggested to selectively attend to gastrointestinal (GI) sensations compared with healthy controls. However, it remains unclear whether there are differences between IBS and other chronic GI disorders. We aimed to evaluate the presence of hypervigilance towards the GI tract in IBS compared with patients with organic GI diseases.

Methods

We included 36 IBS patients and 40 age- and gender-matched patients with organic GI disease. They completed the Hospital Anxiety and Depression Scale (HADS) and underwent three tests: (1) word association—write down as many words as possible representing signs of disease; (2) word recognition (tachistoscope)—four categories of words (positive affects, non-GI symptoms, GI symptoms, negative affects) displayed for increasing time until identified; (3) word recollection—memorize words (10 GI symptoms, 10 positive affects, 10 negative affects).

Results

The word-association task did not show group differences. IBS patients were significantly faster than organic GI patients at recognizing words representing GI symptoms (21 vs. 26 ms; P=.04) and negative affects (27 vs. 34 ms; P=.03), but also tended to be faster at recognizing positive affects (24 vs. 29 ms; P=.08) and non-GI symptoms (22 vs. 27 ms; P=.2). Both groups remembered a similar number of words, but IBS patients tended to recall more incorrect GI words than organic patients (1.3 vs. 1.0; P=.06). There were no group differences in HADS scores.

Conclusion

Compared to patients with organic GI disease, IBS patients seem to be hypervigilant for information regarding GI sensations and maybe also negative information.     

Increased 24-hour urinary cortisol excretion in patients with post-traumatic stress disorder and patients with major depression,but not h patients with fibromyalgia

There is now firm evidence that major depression is accompanied by increased baseline activity of the hypothalamic-pituitary-adrenal (HPA) axis, as assessed by means of 24-h urinary cortisol (UC) excretion. Recently, there were some reports that fibromyalgia and post-traumatic stress disorder (PTSD), two disorders which show a significant amplitude of depressive symptoms, are associated with changes in the baseline activity of the HPA axis, such as low 24-h UC excretion. The aim of the present study was to examine 24-h UC excretion in fibromyalgia and PTSD patients compared to normal controls and patients with major depression. In the three patient groups, severity of depressive symptoms was measured by means of the Hamilton Depression Rating Scale (HDRS) score. Severity of fibromyalgia was measured using a dolorimetrically obtained myalgic score, and severity of PTSD was assessed by means of factor analytical scores computed on the items of the Composite International Diagnostic Interview (CIDI), PTSD Module. Patients with PTSD and major depression had significantly higher 24-h UC excretion than normal controls and fibromyalgia patients. At a threshold value of ≥240 μg/24 h, 80% of PTSD patients and 80% of depressed patients had increased 24-h UC excretion with a specificity of 100%. There were no significant differences in 24-h UC excretion either between fibromyalgia patients and normal controls, or between patients with major depression and PTSD patients. In the three patient groups, no significant correlations were found between 24-h UC excretion and The HDRS score. In fibromyalgia, no significant correlations were found between 24-h UC excretion and the myalgic score. In PTSD, no significant correlations were found between 24-h UC excretion and severity of either depression-avoidance or anxiety-arousal symptoms. In conclusion, this study found increased 24-h UC excretion in patients with PTSD comparable to that in patients with major depression, whereas in fibromyalgia no significant changes in 24-h UC were found.     

Altered cortisol awakening response in posttraumatic stress disorder

An altered function of the hypothalamic-pituitary-adrenal axis is assumed to be characteristic for Posttraumatic Stress Disorder (PTSD), although there is inconsistent empirical evidence. Only few studies examined the awakening cortisol response and a daytime profile in PTSD. Salivary cortisol levels were measured at seven intervals from awakening until 8 PM in trauma-exposed subjects with (N=29) and without PTSD (N=19) and in 15 non-exposed controls. While the three groups did not differ with respect to their first cortisol level immediately after awakening, the expected cortisol increase to awakening 15-60 min later was significantly lower in PTSD patients compared to non-PTSD subjects and healthy controls. This effect remained stable when trauma-exposed subjects with comorbid major depression were excluded from the analysis. A significant negative correlation between the overall cortisol secretion (AUC(G)) and overall PTSD symptomatology and hyper-arousal symptoms was found. The findings are discussed in light of the hypothesis of a counterregulation of hyper-arousal symptoms and chronic stress in PTSD.     

抑郁症患者治疗前后血浆皮质醇水平的变化

目的:探讨抑郁症患者治疗前后血浆皮质醇水平的变化。方法:对160例抑郁症患者给予抗抑郁药治疗6周,分别于治疗前及治疗后进行汉密尔顿抑郁量表(HAMD)、汉密尔顿焦虑量表(HAMA)评估及血浆皮质醇水平检测。结果:本组治疗前后HAMD总分分别为(24.98±5.10)和(7.57±5.61);HAMA总分分别为(20.62±6.90)和(6.21±5.17);血浆皮质醇水平分别为(407.34±144.29)nmol/L和(354.64±137.13)nmol/L。治疗后HAMD总分、HAMA总分及血浆皮质醇水平较治疗前明显下降(P均<0.001);不同性别间血浆皮质醇水平差异无统计学意义(P>0.05);血浆皮质醇变化值与HAMD、HAMA减分率不相关(r=0.084,r=0.049;P均>0.05)。结论:抗抑郁药物治疗可显著降低抑郁症患者血浆皮质醇水平。     

Basal and dexamethasone suppressed salivary cortisol concentrations in a community sample of patients with posttraumatic stress disorder

Background

Posttraumatic stress disorder (PTSD) has been associated with lower concentrations of cortisol and enhanced suppression of cortisol by dexamethasone, although discrepancies exist among reports. The objective of the study was to determine the pattern of cortisol responses in patients seeking treatment for PTSD resulting from a variety of traumatic experiences and to test whether cortisol responses are significantly related to childhood trauma, severity of symptoms, or length of time since trauma.

Methods

Salivary cortisol was measured at 8 am, 4 pm, and 10 pm on 2 consecutive days before and after a 10 pm dose of .5 mg dexamethasone in 17 psychotropic medication and substance-free subjects with PTSD and 17 matched control subjects.

Results

Repeated-measures analysis of variance (ANOVA) of the baseline salivary cortisol concentrations demonstrated a significant effect for group with higher concentrations in the PTSD group but no significant differences in responses to dexamethasone. The presence of childhood abuse did not significantly affect salivary cortisol concentrations, and there was no correlation between predexamethasone cortisol and either the severity of PTSD symptoms or the time since the index trauma.

Conclusions

Neither low basal concentrations nor enhanced suppression of cortisol are consistent markers of a PTSD diagnosis.     

Rectal hypersensitivity as hallmark for irritable bowel syndrome: defining the optimal cutoff

Background Visceral hypersensitivity is a frequently observed hallmark of irritable bowel syndrome (IBS). Studies have reported differently about the presence of visceral hypersensitivity in IBS resulting from lack of standardization of the barostat procedure and due to different criteria used to assess hypersensitivity. We aimed to calculate the optimal cutoff to detect visceral hypersensitivity in IBS. Methods A total of 126 IBS patients and 30 healthy controls (HC) were included for assessment of visceroperception by barostat. Pain perception was assessed on a visual analogue scale (VAS). ROC‐curves were used to calculate optimal discriminative cutoff (pressure and VAS‐score) between IBS patients and HC to define hypersensitivity. Furthermore, pain perception to distension sequences below the pressure threshold for hypersensitivity was defined as allodynia. Key Results Irritable bowel syndrome patients showed increased visceroperception compared to HC. Thresholds for first sensation and first pain were lower in IBS patients VS HC (P < 0.01). ROC‐curves showed optimal discrimination between IBS patients and HC at 26 mmHg with a VAS cutoff ≥20 mm. Using this criterion, hypersensitivity percentages were 63.5% and 6.6% in IBS patients and HC, respectively. No significant differences were observed between IBS subtypes. Allodynia was found in a small number of patients (11%). Conclusions & Inferences Optimal cutoff for visceral hypersensitivity was found at pressure 26 mmHg with a VAS ≥20 mm, resulting in 63.5% of IBS patients being hypersensitive and 11% being allodynic. Standardization of barostat procedures and defining optimal cutoff values for hypersensitivity is warranted when employing rectal barostat measurements for research or clinical purposes.