Anorectal functional disorders in the absence of anorectal inflammation in patients with Crohn's disease

Rectal Urgency Among Patients With Ulcerative Colitis or Crohn's Disease: Analyses from a Global Survey

Background

Rectal urgency is a common but under-reported inflammatory bowel disease (IBD) symptom. The present study assessed the prevalence of rectal urgency and its association with disease activity and patient-reported outcomes (PROs) among patients with ulcerative colitis (UC) or Crohn's disease (CD) in a real-world setting.

Methods

Data were drawn from the 2017-2018 Adelphi IBD Disease Specific Programme™, a multi-center, point-in-time survey of gastroenterologists and consulting adult patients with UC or CD in France, Germany, Italy, Spain, the United Kingdom, and the United States. Gastroenterologists completed patient record forms and patients completed self-reported forms. Analyses were conducted separately for patients with UC or CD. Patient demographics, clinical characteristics, disease activity, symptoms, and PROs were compared between patients with and without rectal urgency.

Results

In total, 1057 patients with UC and 1228 patients with CD were included. Rectal urgency was reported in 20.2% of patients with UC and 16.4% with CD. Patients with rectal urgency were more likely to have moderate or severe disease (UC or CD: P < .0001), higher mean Mayo score (UC: P < .0001), higher mean Crohn's Disease Activity Index score (CD: P < .0001), lower Short IBD Questionnaire scores (UC or CD: P < .0001), and higher work impairment (UC: P < .0001; CD: P = .0001) than patients without rectal urgency.

Conclusions

Rectal urgency is a common symptom associated with high disease activity, decreased work productivity, and worse quality of life. Further studies are needed to include rectal urgency assessment in routine clinical practice to better gauge disease activity in patients with UC or CD.

Anorectal Function and Clinical Characteristics Associated with Faecal Incontinence in Patients with Crohn's Disease

BACKGROUND AND AIMS

Faecal incontinence is an important complaint reported by patients with Crohn's disease [CD] and it is associated with several disease-related mechanisms, including anorectal functional disorders. This study aimed to assess the anorectal function and clinical characteristics to identify parameters associated with faecal incontinence in CD patients.

METHODS

This is a cross-sectional study of 104 patients with CD, aged 18 years or older, from a referral centre between August 2019 and May 2021. Patients responded to a specific questionnaire, and underwent medical record review, proctological examination and anorectal functional assessment with anorectal manometry.

RESULTS

Of the 104 patients, 49% were incontinent. Patients with incontinence had a lower mean resting pressure [43.5 vs 53.1 mmHg; p = 0.038], lower mean squeeze pressure [62.1 vs 94.1 mmHg; p = 0.036] and lower maximum rectal capacity [140 vs 180 mL; p < 0.001]. Faecal incontinence was also associated with disease activity [p < 0.001], loose stools [p = 0.02], perianal disease [p = 0.006], previous anoperineal surgery [p = 0.048] and number of anorectal surgeries [p = 0.036].

CONCLUSIONS

This is the largest reported study describing manometric findings of Crohn's disease patients with and without faecal incontinence. Our results identified an association between faecal incontinence and functional disorders, in addition to clinical features in these patients. Functional assessment with anorectal manometry may help choose the best treatment for faecal incontinence in patients with CD.

Evaluation of Anorectal Function in Perianal Crohn's Disease: A Pilot Study

Background: Perianal Crohn’s disease is a disabling condition, with little known about anorectal function in healed/inactive perianal Crohn’s disease; Aim: To evaluate anorectal function in a cohort of patients with treated/healed perianal Crohn’s disease; Methods: Prospective cohort study, including high-resolution anorectal manometry, balloon expulsion test, and 3D-endoanal ultrasound in all patients; Results: Of the 16 patients studied (mean age ± SD, 42 ± 13 years), 12 (75%) were men. A laceration of the internal anal sphincter and/or anal scarring was seen in nine (56%) patients; there was no laceration of the external anal sphincter. Five (56%) of these nine patients had never experienced faecal incontinence. All had normal anal resting and squeeze pressures. Manometry suggested dyssynergia in 11 (69%) patients, with only one (6%) fulfilling the criteria for obstructed defecation. Hyposensitivity for at least one sensory parameter was seen in 11 (69%) patients and hypersensitivity in five (31%) patients; Conclusions: This study detected sphincter abnormalities in more than half of patients, many of whom were asymptomatic. Alterations in rectal sensation were frequently seen, more commonly with rectal hyposensitivity. Trial registration: ClinicalTrials.gov (NCT03819257).

Functional gastrointestinal disorders in inflammatory bowel disease: Time for a paradigm shift?

Recent advances in biological therapies have revolutionalised and redefined treatment targets in inflammatory bowel disease (IBD). There is now a stronger emphasis on achieving the more stringent therapeutic goals of mucosal and histological healing, rather than clinical remission alone. Consequently, the treatment of refractory “functional” gastrointestinal symptoms, often attributed as the aftermath of previous inflammation, has recently become more prominent in quiescent disease. With further expected advances in anti-inflammatory treatments on the horizon, the burden of such symptoms in quiescent disease, which have been relatively neglected, is set to become an even bigger problem. In this article, we highlight the current state of research and understanding in this field, including recent developments and clinical practice guidelines on the diagnosis and management of functional gastrointestinal symptoms, such as irritable bowel syndrome and functional anorectal and pelvic floor disorders, in patients with quiescent IBD. These disorders are not only highly prevalent in these patients, they are often misdiagnosed, and are difficult to treat, with very few evidence-based therapies. Moreover, they are associated with substantial impairment in quality-of-life, considerable morbidity, and psychological distress. There is therefore an urgent need for a change in emphasis towards earlier recognition, positive diagnosis, and targeted treatment for patients with ongoing functional gastrointestinal symptoms in the absence of active IBD. This article also highlights the need for further research to develop much needed evidence-based therapies.

Abnormal gut motility in inflammatory bowel disease: an update

BACKGROUND

There is substantial evidence linking disturbed gastrointestinal motility to inflammation. Thus, it is not surprising that abnormalities of gastrointestinal motility play a role in inflammatory bowel disease (IBD), affecting patient outcomes. We performed a review of the literature to investigate the relationship between abnormal gut motility and IBD.

METHODS

With an extensive literature search, we retrieved the pertinent articles linking disturbed gut motility to IBD in various anatomical districts.

RESULTS

The evidence in the literature suggests that abnormal gastrointestinal motility plays a role in the clinical setting of IBD and may confuse the clinical picture.

CONCLUSIONS

Abnormal gut motility may be important in the clinical setting of IBD. However, additional data obtained with modern techniques (e.g., magnetic resonance imaging) are needed to individuate in a more precise manner gastrointestinal motor dysfunctions, to understand the nature of clinical manifestations and properly tailor the treatment of patients.

Gastrointestinal motility and absorptive disorders in patients with inflammatory bowel diseases: Prevalence, diagnosis and treatment

Inflammatory bowel diseases (IBD), Crohn`s disease and ulcerative colitis, are chronic conditions associated with high morbidity and healthcare costs. The natural history of IBD is variable and marked by alternating periods of flare and remission. Even though the use of newer therapeutic targets has been associated with higher rates of mucosal healing, a great proportion of IBD patients remain symptomatic despite effective control of inflammation. These symptoms may include but not limited to abdominal pain, dyspepsia, diarrhea, urgency, fecal incontinence, constipation or bloating. In this setting, commonly there is an overlap with gastrointestinal (GI) motility and absorptive disorders. Early recognition of these conditions greatly improves patient care and may decrease the risk of mistreatment. Therefore, in this review we describe the prevalence, diagnosis and treatment of GI motility and absorptive disorders that commonly affect patients with IBD.

Current perspectives on the diagnosis and management of functional anorectal disorders in patients with inflammatory bowel disease

Despite advances in inflammatory bowel disease (IBD) therapies, a significant proportion of patients with quiescent disease experience persistent, debilitating symptoms of faecal incontinence (FI), urgency and defaecatory disorders due to anorectal dysfunction. Such symptoms are often underreported or misdiagnosed and can lead to potentially premature treatment 'escalation' and under-utilisation of pelvic floor investigations. In this review article, we consider putative pathophysiological post-inflammatory changes resulting in altered anorectal sensitivity, motility and neuromuscular coordination and how this may drive symptoms in quiescent IBD. Finally, we discuss a pragmatic approach to investigating and managing anorectal dysfunction and highlight areas for future research for this often-neglected group of patients.

Fecal Incontinence in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Understanding of the prevalence, pathophysiology, and management of fecal incontinence (FI) in inflammatory bowel disease (IBD) patients without an ileal pouch anal anastomosis (IPAA) is suboptimal. We conducted a systematic review and meta-analysis on the prevalence, pathophysiology, and management of primary FI in IBD patients without IPAA.

METHODS

We searched MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews (1966 through March 2017) for studies on the prevalence, physiology, or management of FI in IBD patients without IPAA. A random effects model was used to calculate pooled prevalence rates and odds ratio (OR) with 95% confidence interval (CI). Heterogeneity was assessed with I2 statistics, Cochran Q statistic, and sensitivity analyses.

RESULTS

Seventeen studies were included. Six studies evaluated the prevalence of FI in 4671 IBD patients. There was significant heterogeneity among the studies, but the pooled prevalence of FI among case-control studies was homogeneous at 24% (95% CI 18%-30%, I2 = 50.6%, P = 0.16). FI was more common among IBD patients than non-IBD controls (OR = 7.73; 95% CI 6.26 to 9.84). Therapeutic options were poorly evaluated in uncontrolled studies. Surgery was effective in 70% of patients (7/10), sacral nerve stimulation was effective in 100% of patients (5/5), and 41.6% of patients (5/12) reported subjective improvement in FI with percutaneous tibial nerve stimulation.

CONCLUSIONS

FI is prevalent in IBD patients without IPAA, and more common than non-IBD controls. Additional controlled studies are warranted to further identify effective therapeutic interventions for FI in IBD. 10.1093/ibd/izx109_video1izx109_Video_15760611117001.

Dyssynergic Defecation in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Inflammatory bowel disease (IBD) patients often continue to experience nonspecific gastrointestinal symptoms despite quiescent disease. Unlike non-IBD patients, IBD patients with dyssynergic defecation (DD) may present with various symptoms such as diarrhea, fecal incontinence, constipation, and rectal discomfort. Despite its importance and treatability, DD in IBD patients is not well recognized in practice. We conducted a systematic review and meta-analysis on the prevalence, diagnosis, and management of DD in IBD patients with ongoing defecatory symptoms.

METHODS

We searched MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews (from 1966 through February 2017) to identify relevant studies on the prevalence, diagnostic methods, or management of DD in IBD patients with and without ileal pouch-anal anastomoses (IPAAs). A random effects model was used to calculate the pooled estimates with 95% confidence intervals (CIs). Heterogeneity was assessed with I2 statistics, Cochran Q statistic, and sensitivity analyses.

RESULTS

Seven studies (n = 442) were included. In patients with ongoing defecatory symptoms, the prevalence of DD without IPAA ranged from 45% to 97%, and in patients with IPAA, it ranged from 25% to 75%. The prevalence of DD in IPAA patients with and without pouchitis ranged from 17% to 67% and 29% to 50%, respectively. The pooled response rate to biofeedback therapy in patients without IPAA was 70% (95% CI, 55%-84%; I2 = 95%; P < 0.01), and it was 86% (95% CI, 67%-98%; I2 = 61%; P = 0.05) in those with IPAA.

CONCLUSIONS

Despite limited data, the current literature suggests that DD is highly prevalent in active or quiescent IBD patients with ongoing defecatory symptoms and is responsive to biofeedback therapy. Although more studies are needed, DD should be considered in IBD patients with persistent defecatory symptoms.

Aberrant Motility in Unaffected Small Bowel is Linked to Inflammatory Burden and Patient Symptoms in Crohn's Disease

BACKGROUND

Inflammation-related enteric dysmotility has been postulated as a cause for abdominal symptoms in Crohn's disease (CD). We investigated the relationship between magnetic resonance imaging-quantified small bowel (SB) motility, inflammatory activity, and patient symptom burden.

METHODS

The Harvey-Bradshaw index (HBI) and fecal calprotectin were prospectively measured in 53 patients with CD (median age, 35; range, 18-78 years) the day before magnetic resonance enterography, which included a dynamic (cine), breath-hold motility sequence, repeated to encompass the whole SB volume. A validated registration-based motility quantitation technique produced motility maps, and regions of interest were drawn to include all morphologically normal SB (i.e., excluding diseased bowel). Global SB motility was correlated with calprotectin, HBI, and symptom components (well-being, pain, and diarrhea). Adjustment for age, sex, smoking, and surgical history was made using multivariate linear regression.

RESULTS

Median calprotectin was 336 (range, 0-1280). Median HBI, motility mean, and motility variance were 3 (range, 0-16), 0.33 (0.18-0.51), and 0.01 (0.0014-0.034), respectively. Motility variance was significantly negatively correlated with calprotectin (rho = -0.33, P = 0.015), total HBI (rho = -0.45, P < 0.001), well-being (rho = -0.4, P = 0.003), pain (rho = -0.27, P = 0.05), and diarrhea (rho = -0.4, P = 0.0025). The associations remained highly significant after adjusting for covariates. There was no association between mean motility and calprotectin or HBI (P > 0.05).

CONCLUSIONS

Reduced motility variance in morphologically normal SB is associated with patient symptoms and fecal calprotectin levels, supporting the hypothesis that inflammation-related enteric dysmotility may explain refractory abdominal symptoms in CD.

Neuroplasticity and dysfunction after gastrointestinal inflammation

The gastrointestinal tract is innervated by several distinct populations of neurons, whose cell bodies either reside within (intrinsic) or outside (extrinsic) the gastrointestinal wall. Normally, most individuals are unaware of the continuous, complicated functions of these neurons. However, for patients with gastrointestinal disorders, such as IBD and IBS, altered gastrointestinal motility, discomfort and pain are common, debilitating symptoms. Although bouts of intestinal inflammation underlie the symptoms associated with IBD, increasing preclinical and clinical evidence indicates that infection and inflammation are also key risk factors for the development of other gastrointestinal disorders. Notably, a strong correlation exists between prior exposure to gut infection and symptom occurrence in IBS. This Review discusses the evidence for neuroplasticity (structural, synaptic or intrinsic changes that alter neuronal function) affecting gastrointestinal function. Such changes are evident during inflammation and, in many cases, long after healing of the damaged tissues, when the nervous system fails to reset back to normal. Neuroplasticity within distinct populations of neurons has a fundamental role in the aberrant motility, secretion and sensation associated with common clinical gastrointestinal disorders. To find appropriate therapeutic treatments for these disorders, the extent and time course of neuroplasticity must be fully appreciated.

Electrocautery-induced localized colonic injury elicits increased levels of pro-inflammatory cytokines in small bowel and decreases jejunal alanine absorption

BACKGROUND

Colitis is associated with functional abnormalities in proximal non-inflamed gut areas, but animal models to study small bowel dysfunction in colitis have limitations. This study aims to determine small intestinal alanine absorption and cytokine expression in a novel model of colonic ulceration induced by electro-cautery.

METHODS

A descending colon ulcer was induced in rats by a bipolar electro-cautery probe. Ulcer score was determined using Satoh's criteria. Jejunal alanine absorption was measured immediately and at different time intervals post ulcer induction. Levels of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) protein and m-RNA were determined in mucosal scrapings obtained from the colon, duodenum, jejunum and ileum at various time intervals after colonic ulcer induction.

RESULTS

The mean ulcer score was 3 up to 48h, followed by healing by 96h post ulcer induction. Small bowel histology was normal throughout. Jejunal alanine absorption was reduced by 12-34% immediately and up to 72h after cautery and returned to normal at 96h. IL-1 and TNF-α mRNA increased significantly in the colon, duodenum, jejunum and ileum 3h post electro-cautery and returned to normal at 48h, while that of IL-6 increased significantly at 48h post ulcer induction. Similarly, IL-1, IL-6 and TNF-α protein levels increased in the duodenum, jejunum, ileum and colon up to 48h post ulcer induction.

CONCLUSIONS

Electrically induced localized colonic injury increased production of pro-inflammatory cytokines in non-inflamed segments of the small intestine and was associated with derangements of jejunal absorptive function.

Anorectal complications and function in patients suffering from inflammatory bowel disease: a series of patients with long-term follow-up

AIM

The aim of this study is to describe the long-term course of anorectal complains and function in a single centre cohort patients suffering from inflammatory bowel disease (IBD) with perianal lesions.

METHODS

Between 1993 and 2000, 56 IBD patients (43 Crohn's disease and 13 ulcerative colitis) with perianal complaints underwent anorectal function evaluation (AFE) (baseline). For follow-up, they were approached between 2010 and 2012 by sending questionnaires including Inflammatory Bowel Disease Quality of Life Questionnaire (IBDQ), Perianal Disease Activity Index (PDAI), faecal incontinence scale (Vaizey) and an invitation for AFE.

RESULTS

At follow-up, 46 patients (82 %) were available, 9 (16 %) were lost and 1 (2 %) had died. Thirty patients returned the questionnaires of which 17 also underwent AFE. The remaining 16 patients were interviewed by phone and were only willing to mention their anorectal complaints. Median follow-up was 14 year. In 25 of the 46 patients (54 %), perianal complaints persisted faecal incontinence (n = 7); soiling (n = 13) and active fistula (n = 5). Eighteen (39 %) patients had an active fistula at baseline and three persisted at follow-up. Two developed a new fistula. Mean IBDQ, Vaizey and PDAI were 178 (SD 29), 7 (SD 5) and 4.2 (SD 3.0), respectively. In 17 patients, who underwent AFE, anal endosonography showed healing in nine of the ten fistulas. Anal pressures as well as rectal capacity remained unaltered in the individual patient, but showed a large range within the group.

CONCLUSION

After 14 years, 54 % of the IBD patients with perianal lesions still have mild complaints. The quality of life remained moderate over a long period, which is concerning.

Dyssynergic defecation: a treatable cause of persistent symptoms when inflammatory bowel disease is in remission

BACKGROUND

Introduction of biologic agents in inflammatory bowel disease (IBD) has increased the likelihood of disease remission. Despite resolution of active inflammation, a subset of IBD patients report persistent defecatory symptoms.

AIM

To evaluate a group of patients with inflammatory bowel disease with suspected functional defecatory disorders, by use of anorectal manometric testing and subsequent biofeedback therapy.

METHODS

A group of IBD patients with persistent defecatory problems despite clinical improvement were included in this study. These patients had no evidence of left-sided disease. Endoscopic and radiographic study findings and timing in relation to the manometry study were recorded. Anorectal manometry was performed by the standard protocol and included rectal sensory assessment, ability to expel a balloon, and pressure dynamics with simulated defecation.

RESULTS

Thirty IBD patients (Crohn's 23 patients; ulcerative colitis six patients) presented with defecatory disorders including constipation (67%) increased stooling (10%), and rectal urgency and/or incontinence and rectal pain (6%). All but one patient had anorectal manometric criteria of dyssynergia (presence of anismus motor pattern and inability to expel the balloon). Of the patients who completed biofeedback therapy, 30% had a clinically significant (≥7-point) improvement in SIBDQ score, with a reduction in health-care utilization after a six-month period (p=0.02).

CONCLUSIONS

Despite remission, some inflammatory bowel disease patients have persistent defecatory symptoms. Defecatory symptoms may not be predictive of an underlying inflammatory disorder. Lack of inflammatory activity and absence of left-sided disease should prompt investigation of functional disorders. Anorectal manometric testing and biofeedback therapy for patients with a diagnosis of dyssynergia may be a useful therapy.

Severity of fecal urgency and incontinence in inflammatory bowel disease: clinical, manometric and sonographic predictors

BACKGROUND

Fecal incontinence (FI) and urgency are prevalent symptoms in patients with inflammatory bowel diseases (IBD). It is unclear which factors determine their severity. We evaluated associations of clinical activity, anorectal motility, and endoanal sonography with FI severity in IBD.

METHODS

Fifty-eight consecutive IBD patients and 14 healthy volunteers participated in a cross-sectional, tertiary-center study. Active disease was defined as Crohn's disease activity index ≥ 150 and as simple clinical colitis index > 2. We assessed anal pressures and fatigue rate index (FRI) of the external anal sphincter (EAS) by manometry, rectal compliance and sensitivity by balloon distension, and sphincter defects by endoanal ultrasound. Significant bivariate associations between these parameters and the fecal incontinence severity scale (FISS) were evaluated in multivariate analysis.

RESULTS

Twenty-seven patients (47%) reported urgency, 13 of which (22%) reported FI. Defects of the internal anal sphincter (IAS) and the EAS were diagnosed in 14 (24%) and 13 patients (22%), respectively. Patients had significantly lower rectal compliance and FRI compared with controls. FISS demonstrated significant bivariate associations with clinical disease activity (P = 0.0115), FRI (P = 0.0018), sonographic IAS and EAS defects (P < 0.0001 and 0.0059), rectal compliance (P = 0.0001), and volume at the threshold of a constant urge (Vurge, P = 0.0002). In multivariate analysis, FISS was associated with clinical disease activity (P = 0.0325), FRI (P = 0.0367), Vurge (P = 0.0091), and sonographic IAS defect(s) (P = 0.0008). The derived model explained 62% of the variance in FISS (P < 0.0001).

CONCLUSIONS

Clinical disease activity and manometric and sonographic anorectal parameters are associated with FI severity in IBD. Prospective studies are warranted to evaluate their predictive value in continence outcomes.

Up-regulation of nerve growth factor and interleukin-10 in inflamed and non-inflamed intestinal segments in rats with experimental colitis

Inflammatory bowel diseases are characterized by dysregulated immune response to the normal microflora and structural and functional changes of the enteric nervous system which occur in inflamed as well as non-inflamed areas of the bowel. This study describes the changes in the expression of nerve growth factor (NGF) and interleukin-10 (IL-10) in the colon and in various segments of the small intestine in two rat models of experimental colitis induced by iodoacetamide or 2,4,6-trinitrobenzene sulfonic acid (TNBS). Levels of NGF and IL-10 were measured by ELISA in tissue homogenate sampled from duodenum, jejunum, ileum and colon at different time intervals. NGF and IL-10 increased significantly in homogenates of strips isolated from all small intestinal segments, 3-6h after iodoacetamide or TNBS administration and remained elevated until the colonic inflammation subsided. Similar but more pronounced increase occurred in areas of the colon adjacent to the ulcer. Histologic examinations revealed inflammatory changes in the colon; however, examination of sections from the small intestines did not reveal significant differences between controls and rats with colitis. The marked up-regulation of nerve growth factor and interleukin-10 in colitis suggests that they play a role in limiting or resolving inflammation and in preventing it from becoming uncontrolled. It also suggests that experimental colitis may be associated with latent inflammation in the small bowel.

Differential responses of VIPergic and nitrergic neurons in paediatric patients with Crohn's disease

Inflammatory bowel disease is a recurrent intestinal inflammatory disorder that in adults has been associated with changes in enteric nervous system neuropeptide expression. The aim of the present study was to determine whether similar changes were observed in paediatric Crohn's disease. The distribution of vasoactive intestinal peptide (VIP) and neuronal nitric oxide synthase (nNOS) was determined in colonic tissues from children with ileo-colonic (n=4) and colonic (n=3) Crohn's disease. The submucosal plexus of inflamed regions showed significant increase in density of VIP immunoreactive neurons (margin, 48% vs. inflamed tissue, 82% of HuC/D positive neurons). The density of submucosal plexus nNOS immunoreactive neurons was too low to be reliably quantified. Using the pan-neuronal marker HuC/D, no significant difference in numbers of HuC/D positive submucosal neurons was evident except where neurons were normalized to length of tissue (margins, 3.6+/-0.7 vs. inflamed tissue, 4.0+/-0.6 neurons/ganglia, p=0.33; margins, 2.7+/-0.4 vs. inflamed tissue, 5.7+/-1.2, neurons/mm, p=0.03). In the myenteric plexus, there was a significant increase in the percent of NOS neurons (38% vs. 82% of HuC/D positive neurons) while there was no significant difference in percent of VIP neurons (4% vs. 8%). No difference in number of HuC/D positive myenteric neurons among margin and inflamed tissues was observed (margin, 12.2+/-3.0 vs. inflamed tissue, 12.5+/-5.1 neurons/ganglia, p=0.50; margins 9.1+/-2.1 vs. inflamed tissue, 13.7+/-2.3 neurons/mm, p=0.11). These data demonstrate that inflammation is associated with a differential expression of VIP and nNOS neuronal subpopulations within the two major enteric plexi, likely due to phenotypic switch. Such changes might contribute to the pathogenesis of IBD and ongoing symptoms even in quiescent disease.

Substance P and other neuropeptides do not induce mediator release in isolated human intestinal mast cells

Neuropeptides such as substance P (SP) and related peptides are supposed to act as mast cell agonists, and thus as mediators of neuroimmune interactions. The data supporting this hypothesis were obtained mostly from rodent experiments. Here, we studied for the first time the effect of SP and other peptides on mediator release in human intestinal mast cells, either unpurified or enriched to 85-99% purity. We found that SP at 0.1-100 micromol L(-1), or other peptides including neurokinin A and B, calcitonin gene-related peptide, vasoactive intestinal peptide and serotonin at 1 micromol L(-1) do not induce release of mediators such as histamine, sulphidoleukotrienes, and tumour necrosis factor alpha. The peptides also failed to cause mediator release in mast cells isolated from inflamed tissue derived from Crohn's disease. Using reverse transcriptase-polymerase chain reaction, flow cytometry and immunohistochemistry, we could show that human intestinal mast cells do not express the tachykinin receptors NK-1, NK-2, or NK-3 under basal conditions. However, upon stimulation by immunoglobulin E (IgE) receptor-crosslinking, which induces an extensive mediator release reaction, a subpopulation of mast cells clearly expressed NK-1, the SP receptor. In conclusion, our data show that SP and other neuropeptides do not act as secretagogues in human intestinal mast cells that have not been pre-activated by IgE receptor-crosslinking.

Increased anal resting pressure and rectal sensitivity in Crohn's disease

PURPOSE

Anal pathology occurs in 20 to 80 percent of patients with Crohn's disease in which abscesses, fistulas, and fissures account for considerable morbidity. The etiology is not clearly defined, but altered anorectal pressures may play a role. This study was designed to investigate anorectal physiologic conditions in patients with Crohn's disease compared with healthy controls.

METHODS

Twenty patients with Crohn's disease located in the ileum (n = 9) or the colon (n = 11) without macroscopic proctitis or perianal disease were included. All were subjected to rectal examination, anorectal manometry, manovolumetry, and rectoscopy. Comparison was made with a reference group of 173 healthy controls of whom 128 underwent anorectal manometry, 29 manovolumetry, and 16 both examinations.

RESULTS

Maximum resting pressure and resting pressure area were higher in patients than in controls (P = 0.017 and P = 0.011, respectively), whereas maximum squeeze pressure and squeeze pressure area were similar. Rectal sensitivity was increased in patients expressed as lower values both for volume and pressure for urge (P = 0.013 and P = 0.014, respectively) as well as maximum tolerable pressure (P = 0.025).

CONCLUSIONS

This study demonstrates how patients with Crohn's disease without macroscopic proctitis have increased anal pressures in conjunction with increased rectal sensitivity. This may contribute to later development of anal pathology, because increased intra-anal pressures may compromise anal circulation, causing fissures, and also discharging of fecal matter into the perirectal tracts, which may have a role in infection and fistula development.