Immunohistochemical study of the colonic muscle and innervation in idiopathic chronic constipation

Submucosal Nerve Diameter in the Rectum Increases With Age: An Important Consideration for the Diagnosis of Hirschsprung Disease

INTRODUCTION

Hypertrophic submucosal nerves, defined as ≥40 µm in diameter, are considered supportive of a diagnosis of HSCR, but the effect of age on nerve diameter has not been well-studied. We sought to determine the distribution of the largest nerve diameter in ganglionic rectal biopsies and the significance of hypertrophic submucosal nerves in the diagnosis of Hirschsprung disease (HSCR) based on age.

METHODS

Rectal biopsies performed in the evaluation of HSCR were retrospectively reviewed from 179 patients (151 ganglionic biopsies, 28 aganglionic biopsies), and the diameter of the largest submucosal nerve was measured.

RESULTS

In non-Hirschsprung disease (non-HSCR) biopsies, submucosal nerve diameter increased with age. In patients <1 year, the average diameter was 34.1 ± 11.6 µm but increased to 50.8 ± 17.3 µm after 1 year of age. Submucosal nerves ≥40 µm in diameter were significantly associated with HSCR across all ages [HSCR = 25/28 (89.3%) vs non-HSCR = 59/151 (39.1%), p < 0.0001] and remained significant in patients <1 year of age [HSCR = 22/24 (91.7%) vs non-HSCR = 19/91 (20.9%), p < 0.0001].

CONCLUSIONS

The diameter of submucosal nerves increases with age, and ≥40 µm nerves are common after 1 year of age.

Cystic fibrosis transmembrane conductance regulator modulates enteric cholinergic activities and is abnormally expressed in the enteric ganglia of patients with slow transit constipation

BACKGROUND

Cystic fibrosis transmembrane conductance regulator (CFTR) was recently found in the enteric nervous system, where its role is unclear. We aimed to identify which enteric neuronal structures express CFTR, whether CFTR modulates enteric neurotransmission and if altered CFTR expression is associated with slow transit constipation (STC).

METHODS

Immunofluorescence double labeling was performed to localize CFTR with various neuronal and glial cell markers in the human colon. The immunoreactivity (IR) of CFTR and choline acetyltransferase (ChAT) on myenteric plexus of control and STC colon was quantitatively analyzed. In control colonic muscle strips, electrical field stimulation (EFS) evoked contractile responses and the release of acetylcholine (ACh) was measured in the presence of the CFTR channel inhibitor, CFTR(inh)-172.

RESULTS

CFTR-IR was densely localized to myenteric ganglia, where it was co-localized with neuronal markers HuC/D and β-tubulin, and glial marker S-100 but little with glial fibrillary acidic protein. Vesicular ACh transport was almost exclusively co-localized with CFTR, but neurons expressing nitric oxide synthase were CFTR negative. Significant reductions of CFTR-IR (P < 0.01) and ChAT-IR (P < 0.05) were observed on myenteric ganglia of STC compared to control. Pre-treatment of colonic muscle strips with CFTR(inh)-172 (10 µM) significantly inhibited EFS-evoked contractile responses (P < 0.01) and ACh release (P < 0.05).

CONCLUSIONS

Co-localization of CFTR-IR with cholinergic markers, inhibition of EFS-induced colonic muscle contractility and ACh release by CFTR(inh)-172 suggest that CFTR modulates enteric cholinergic neurotransmission. The downregulation of CFTR and ChAT in myenteric ganglia of STC correlated with the impaired contractile responses to EFS.

Indian consensus on chronic constipation in adults: A joint position statement of the Indian Motility and Functional Diseases Association and the Indian Society of Gastroenterology

The Indian Motility and Functional Diseases Association and the Indian Society of Gastroenterology developed this evidence-based practice guideline for management of chronic constipation. A modified Delphi process was used to develop this consensus containing 29 statements, which were generated by electronic voting iteration as well as face to face meeting and review of the supporting literature primarily from India. These statements include 9 on epidemiology, clinical presentation, and diagnostic criteria; 8 on pathophysiology; and the remaining 12 on investigations and treatment. When the proportion of those who voted either to accept completely or with minor reservation was 80% or higher, the statement was regarded as accepted. The members of the consensus team believe that this would be useful for teaching, clinical practice, and research on chronic constipation in India and in other countries with similar spectrum of the disorders.

Associated Factors for Antegrade Continence Enemas for Refractory Constipation and Fecal Incontinence

OBJECTIVE

Determine clinical and manometric parameters associated with success of antegrade continence enemas (ACEs) administered via cecostomy in the treatment of constipation and fecal overflow incontinence.

METHODS

We performed a retrospective review of clinical symptoms and manometry (colonic and anorectal) before cecostomy in 40 pediatric patients (20 males, 20 females). The mean age at time of follow-up was 9.5 ± 4.4 years with a mean follow-up time of 12.2 ± 10.9 months. Clinical outcomes were defined as good, if subjects had >3 bowel movements per week, <2 episodes of soiling per week, and absence of pain at the time of follow-up after cecostomy.

RESULTS

Before cecostomy, the mean duration of constipation and/or fecal incontinence was 7.7 ± 4.4 years, mean number of BMs was 1.5 ± 0.9 per week, and soiling episodes 4.12 ± 3.5 per week; 24 (60%) patients had abdominal pain. At follow-up 30 out of 40 patients had a good outcome, and 10 had a poor outcome; with a difference in the number of weekly BM of 5.7 ± 2.2 versus 1.5 ± 0.9, P < 0.001, and soiling episodes (0.4 ± 1.5 vs 4 ± 3.1, P < 0.001). There was no difference in the duration of symptoms between groups. Obesity was more common in the poor-outcome group, 60% versus 21% (P = 0.01). Abdominal pain was more common in the poor-outcome group, 100% versus 47% (P = 0.003). Normal colonic manometry was associated with good outcome, whereas absence of high-amplitude propagating contraction (HAPC) in any part of the colon was associated with poor outcome. No other differences in colonic manometry were observed between the good- and poor-outcome groups with the exception of a trend toward decreased number of sigmoid HAPCs in the poor-outcome group (P = 0.07). No differences were observed in anorectal manometry measurements between good- and poor-outcome groups with the exception of an observable increased baseline resting pressure in the poor outcome (P = 0.05).

CONCLUSIONS

Obesity and abdominal pain tend to be associated with poor outcomes after cecostomy for refractory constipation. Normal colonic and anorectal manometry were associated with good outcome. Absence of HAPC in any part of the colon, and increased baseline resting pressure of the anal canal were more associated with poor outcome. No other specific differences in either colonic or anorectal manometric parameters were observed in patients with good versus poor outcomes with cecostomy. Large prospective studies potentially combining other diagnostic modalities such as colonic transit studies are needed to determine the optimal tests to predict successful outcomes from cecostomy.

Comparison of two types of colectomy in treating slow transit constipation with or without melanosis coli

AIM: To compare the follow-up outcomes of ileosigmoidal anastomosis (ISA) and caecorectal anastomosis (CRA) in patients with slow transit constipation (STC) with or without melanosis coli (MC).

METHODS: We collected the clinical data of 48 STC patients with or without MC from May 2002 to May 2007. Twenty-six patients underwent CRA (14 with MC) and 22 cases received ISA (14 with MC). A 3-year postoperative follow-up was conducted.

RESULTS: CRA improved the quality of life [evaluated by the gastrointestinal quality of life index (GIQLI)] in patients without MC, but was inferior to ISA in stool frequency and Wexner and GIQLI scores for MC patients. In the CRA group, patients with MC suffered worse outcomes than those without MC.

CONCLUSION: CRA is more suitable for STC patients without MC; however, for STC patients with MC, ISA is a better choice.

Chronic constipation and treatment options (Review)

Chronic constipation (CC) is a highly prevalent heterogeneous disorder. Although CC is not known to be associated with the development of serious disease or with excess mortality, it considerably reduces the patients quality of life. In addition, it represents an economic burden to patients and society. The majority of patients with CC successfully manage the disorder by dietary management and the use of laxatives. Patients with functional CC (slow‑transit and non‑slow transit constipation) do not respond to laxatives and are a small fraction of the total population complaining of constipation. Regardless of the low number of these patients, the intractability of their symptoms causes psychological and social stress and greatly impairs their quality of life. Furthermore, these patients consume a disproportionate quantity of medical resources. It appears that these patients have a disturbance in the serotonin transmission system, which results in a cascade of alterations in a number of gut neuroendocrine hormones/transmitters. The effect of prucalopride, a serotonin receptor agonist, in this category of patients appears to be not only a pharmacological prokinetic action, but also a correction of a pre‑existing disturbance. Linaclotide, a member of the guanylin peptide family, binds to the ligand‑binding region of guanylate cyclase‑C on the luminal surface of gastrointestinal epithelia resulting in increased fluid secretion. This drug has also been found to be effective for the treatment of functional CC. In addition, biofeedback and sacral nerve stimulation are effective in the treatment of CC caused by pelvic floor disorders.

Cellular and molecular basis of chronic constipation: Taking the functional/idiopathic label out

In recent years, the improvement of technology and the increase in knowledge have shifted several strongly held paradigms. This is particularly true in gastroenterology, and specifically in the field of the so-called “functional” or “idiopathic” disease, where conditions thought for decades to be based mainly on alterations of visceral perception or aberrant psychosomatic mechanisms have, in fact, be reconducted to an organic basis (or, at the very least, have shown one or more demonstrable abnormalities). This is particularly true, for instance, for irritable bowel syndrome, the prototype entity of “functional” gastrointestinal disorders, where low-grade inflammation of both mucosa and myenteric plexus has been repeatedly demonstrated. Thus, researchers have also investigated other functional/idiopathic gastrointestinal disorders, and found that some organic ground is present, such as abnormal neurotransmission and myenteric plexitis in esophageal achalasia and mucosal immune activation and mild eosinophilia in functional dyspepsia. Here we show evidence, based on our own and other authors’ work, that chronic constipation has several abnormalities reconductable to alterations in the enteric nervous system, abnormalities mainly characterized by a constant decrease of enteric glial cells and interstitial cells of Cajal (and, sometimes, of enteric neurons). Thus, we feel that (at least some forms of) chronic constipation should no more be considered as a functional/idiopathic gastrointestinal disorder, but instead as a true enteric neuropathic abnormality.

Surgical outcomes after total colectomy with ileorectal anastomosis in patients with medically intractable slow transit constipation

Purpose

The aim of this study was to evaluate outcomes of a total colectomy with ileorectal anastomosis in patients with slow transit constipation.

Methods

A retrospective review of 37 consecutive patients with slow transit constipation who underwent a total colectomy between 1994 and 2008 was undertaken. Preoperative and postoperative Wexner's constipation scores were collected and used to evaluate the outcomes after surgical treatment. Also patients' postoperative satisfaction scores were collected using a 4-point scale.

Results

The 37 patients consisted of 31 women and 6 men, with a median age of 41 years (range, 17 to 71 years). Pre- and post-operative Wexner's scores were collected from 33 patients (89.1%), and the mean preoperative Wexner's score was 19.3 (range, 11 to 24), which decreased to an average post-operative score of 2.3 (range, 0 to 8). Neither intraoperative complications nor postoperative mortalities were noted. Five patients (13.5%) had early postoperative complications, and the most common complication was postoperative ileus (10.8%). Seven patients (18.9%) had late postoperative complications, and postoperative ileus (10.8%) was also the most common. Twenty seven of 33 patients were satisfied with their surgical outcome (81.8%).

Conclusion

A total colectomy with ileorectal anastomosis might be an effective surgical procedure with acceptable morbidity to treat medically intractable slow transit constipation.

Gastrointestinal neuromuscular pathology in chronic constipation

Some patients with chronic constipation may undergo colectomy yielding tissue appropriate to diagnosis of underlying neuromuscular pathology. The analysis of such tissue has, over the past 40 years, fueled research that has explored the presence of neuropathy, myopathy and more recently changes in interstitial cells of Cajal (ICC). In this chapter, the data from these studies have been critically reviewed in the context of the significant methodological and interpretative issues that beset the field of gastrointestinal neuromuscular pathology. On this basis, reductions in ICC appear to a consistent finding but one whose role as a primary cause of slow-transit constipation requires further evaluation. Findings indicative of significant neuropathy or myopathy are variable and in many studies subject to considerable methodological bias. Methods with practical diagnostic utility in the individual patient have rarely been employed and require further validation in respect of normative data.

Ultraviolet-A irradiation to the eye modulates intestinal mucosal functions and properties of mast cells in the mouse

We previously reported that topical irradiation of the eye by ultraviolet-B (UVB) activated hypothalamo-pituitary-adrenal axis (HPA-A) of the mouse to increase 3, 4-dihydroxyphenylalanine (DOPA)-positive melanocytes in the skin by an inducible nitric oxide synthase (iNOS)-dependent mechanism. This work demonstrates that irradiation of the eye by ultraviolet-A (UVA) specifically increased DOPA-positive cells in the mucosa of the jejunum and colon of C57BL/6J mice by some HPA- and iNOS-independent mechanism. UVA-induced increase in DOPA-positive cells in the intestine was inhibited by the administration of hexamethonium or prazosin plus propranolol, blockers for the sympathetic nervous system. UVA irradiation of the eye increased DOPA- and histidine decarboxylase (HDC)-positive cells in the intestinal mucosa of both C57BL/6J and WBB6F1/J mice but not in the mutant strain W/Wv of the latter that lack mast cells. UVA irradiation of the eye suppressed the intestinal peristalsis of control, hypophysectomized or iNOS(-/-) C57BL/6J mice by the mechanism that was inhibited by hexamethonium or prazosin plus propranolol. These observations suggest that UVA irradiation of the eye stimulated the sympathetic nervous system to increase the mucosal DOPA- and HDC-positive mast cells and suppressed the peristalsis of the small intestine of the mouse.

Autonomic denervation and the origins of chronic Western diseases

Many chronic Western diseases result from lifestyles that include refined diets, poor bowel habits, limited physical exercise and suboptimal patterns of childbirth. Western diets result in reduced stool weights, increased bowel transit times and persistent physical efforts during defaecation. Prolonged physical efforts during defaecation and childbirth cause latent, or direct, injuries to branches of the cardiac (thorax), coeliac (abdomen) and hypogastric (pelvis) plexi. Injuries to autonomic nerves result in impaired visceral function including visceral dysmotility, tissue hypoplasia and hyperplasia, increased susceptibility to infection, and, aberrant reinnervation with sensitisation of the central nervous system (CNS). These unrecognised injuries are vulnerable to the long list of causes of autonomic Dysfunction, e.g. stress, alcohol, drugs, infection, trauma, cancer, etc. Specific injuries at different anatomical locations in midline autonomic pathways give rise to a wide range of Western diseases from infancy to old age, through diverse and cumulative mechanisms.

Gastrointestinal neuromuscular pathology: guidelines for histological techniques and reporting on behalf of the Gastro 2009 International Working Group

The term gastrointestinal neuromuscular disease describes a clinically heterogeneous group of disorders of children and adults in which symptoms are presumed or proven to arise as a result of neuromuscular, including interstitial cell of Cajal, dysfunction. Such disorders commonly have impaired motor activity, i.e. slowed or obstructed transit with radiological evidence of transient or persistent visceral dilatation. Whilst sensorimotor abnormalities have been demonstrated by a variety of methods in these conditions, standards for histopathological reporting remain relatively neglected. Significant differences in methodologies and expertise continue to confound the reliable delineation of normality and specificity of particular pathological changes for disease. Such issues require urgent clarification to standardize acquisition and handling of tissue specimens, interpretation of findings and make informed decisions on risk-benefit of full-thickness tissue biopsy of bowel or other diagnostic procedures. Such information will also allow increased certainty of diagnosis, facilitating factual discussion between patients and caregivers, as well as giving prognostic and therapeutic information. The following report, produced by an international working group, using established consensus methodology, presents proposed guidelines on histological techniques and reporting for adult and paediatric gastrointestinal neuromuscular pathology. The report addresses the main areas of histopathological practice as confronted by the pathologist, including suction rectal biopsy and full-thickness tissue obtained with diagnostic or therapeutic intent. For each, indications, safe acquisition of tissue, histological techniques, reporting and referral recommendations are presented.

Regional variation in the neurochemical coding of the myenteric plexus of the human colon and changes in patients with slow transit constipation

There are differences in the structure and function between regions of the colon. In patients with slow transit constipation the activity of all regions is markedly slowed. Counts of colonic neurones in slow transit constipation have been semiquantitative and led to varying results. We have applied new methods of quantification of markers in whole mounts of the colonic myenteric plexus to compare density of innervation between regions and between normal patients and those undergoing resection for severe constipation. Whole mounts of colonic myenteric plexus were made from specimens removed for cancer treatment (controls) and cases of severe constipation. All neurones were labelled by anti-human neuronal protein antibodies. Neurones synthesizing acetyl choline were labelled for choline acetyltransferase (ChAT) and those for nitric oxide by antisera to nitric oxide synthase (NOS). Four populations of neurones were distinguished and quantified according to the two selective markers, ChAT and NOS. In the normal major populations were NOS alone (51% of ascending colon neurones and 44% of descending colon neurones) and ChAT alone (41% ascending colon, 48% descending colon). Nitric oxide synthase/ChAT and NOS-/ChAT-comprised only small populations. In all regions in severe constipation, the percentage of NOS-only colonic myenteric neurones was raised (54% ascending colon, 49% descending colon) and ChAT only was reduced (36% ascending colon, 42% descending colon). The other populations were not changed. Accurate quantification of neuronal populations in whole mounts of human colon reveals inter-regional differences in innervation and marked changes in innervation in cases of very severe constipation.

Slow transit constipation: A functional disorder becomes an enteric neuropathy

Slow transit constipation has been traditionally considered and classified as a functional disorder. However, clinical and manometric evidence has been accumulating that suggests how most of the motility alterations in STC might be considered of neuropathic type.In addition, further investigations showed that subtle alterations of the enteric nervous system, not evident to conventional histological examination, may be present in these patients. In the present article we will discuss these evidences, and will try to put them in relation with the abnormal motor function of the large bowel documented in this pathological condition.

Interstitial cells of cajal in patients with constipation due to total colonic inertia

Colonic wall contains interstitial cells of Cajal. In view of studies demonstrating that Cajal cells generate electric waves which are presumably responsible for colonic motor activity, and that these waves are absent in total colonic inertia, we investigated the hypothesis that colonic Cajal cells might be disordered in patients with total colonic inertia. The study comprised 28 patients (age 41.6 +/- 8.2 SD years, 19 women, 9 men) with total colonic inertia in whom total colectomy was performed. Colonic specimens obtained from normal segments of the excised colon of 24 cancer patients acted as controls. Specimens were subjected to c-kit immunohistochemistry. Controls for antisera specificity consisted of tissue incubated with normal rabbit serum that had been substituted for the primary antiserum. C-kit-positive branched Cajal-like cells were detected in the musculature of the normal colonic segments. They were distinguishable from the C-kit-negative smooth muscle cells and the C-kit-positive but unbranched mast cells. No Cajal cells were detected in colon of total colonic inertia patients. The absence of Cajal cells in patients with total colonic inertia can be assumed to explain the absence of electric waves and motile activity previously reported in these patients. Further studies are needed to investigate the cause of Cajal-cell absence.

Small bowel transit does not correlate with outcome of surgery in patients with colonic inertia

Colonic inertia is a motility disorder that may involve dysfunction of the entire intestinal tract. The aim of this study was to assess whether small bowel transit time is associated with the outcome of total abdominal colectomy in patients with colonic inertia. A retrospective review of the medical records of patients who underwent total abdominal colectomy for colonic inertia was performed to identify those individuals who had a preoperative small bowel transit study. The outcome of surgery was correlated with the results of the small bowel transit study. Fifty-two female patients underwent total abdominal colectomy for colonic inertia between 1988 and 2000, of whom 17 (33%) had a preoperative small bowel transit study. The small bowel transit time was normal in 11 patients (65%), and the time was abnormally prolonged in 6 (35%). At a mean follow-up of 37 months, there was no significant difference in the outcome of surgery between the two groups. A good result was achieved in 36% of the normal small bowel transit time group compared with 33% in the abnormal group; the result was fair in 63% and 33%, and poor in 0% and 33%, respectively (P=NS). The small bowel transit study does not reliably predict the outcome of total abdominal colectomy in patients with colonic inertia.

The role of glial cells and apoptosis of enteric neurones in the neuropathology of intractable slow transit constipation

BACKGROUND

Idiopathic slow transit constipation is one of the most severe and often intractable forms of constipation. As motor abnormalities are thought to play an important pathogenetic role, studies have been performed on the colonic neuroenteric system, which rules the motor aspects of the viscus.

AIMS

We hypothesised that important neuropathological abnormalities of the large bowel are present, that these are not confined to the interstitial cells of Cajal and ganglion cells, and that the previously described reduction of enteric neurones, if confirmed, might be related to an increase in programmed cell death (apoptosis).

PATIENTS AND METHODS

Surgical specimens from 26 severely constipated patients were assessed by conventional and immunohistochemical methods. Specific staining for enteric neurones, glial cells, interstitial cells of Cajal, and fibroblast-like cells associated with the latter were used. In addition, gangliar cell apoptosis was evaluated by means of indirect and direct techniques. Data from patients were compared with those obtained in 10 controls.

RESULTS

Severely constipated patients displayed a significant decrease in enteric gangliar cells, glial cells, and interstitial cells of Cajal. Fibroblast-like cells associated with the latter did not differ significantly between patients and controls. Patients had significantly more apoptotic enteric neurones than controls.

CONCLUSION

Severely constipated patients have important neuroenteric abnormalities, not confined to gangliar cells and interstitial cells of Cajal. The reduction of enteric neurones may in part be due to increased apoptotic phenomena.

Decreased density of interstitial cells of Cajal and neuronal cells in patients with slow-transit constipation and acquired megacolon

BACKGROUND

The pathophysiology of constipation is not clearly identified as yet, and the interstital cells of Cajal (ICC), known to generate the slow wave activity and to be involved in intestinal neurotransmission and the enteric nervous system (ENS), are suspected to play an important role. The aims of the present study were to assess the distribution of ICC and neuronal cells of ENS in patients with slow-transit constipation and acquired megacolon.

METHODS

Sigmoid colon specimens were obtained from patients who underwent colectomy due to slow-transit constipation (n = 10), acquired megacolon (n = 9) and non-obstructive colon cancer (n = 10) as a control group. The ICC were visualized by c-Kit immunohistochemistry and neuronal cells of the ENS were demonstrated by protein gene product (PGP) 9.5. Density of cells stained by c-Kit and PGP 9.5 was calculated as percent area (area stained/area of X-Y plane) x 100, when images were collected at a magnification of x40 objective, with maximum area examined in the horizontal X-Y plane of 400 microm x 400 microm using an image analyzer.

RESULTS

The densities of ICC and PGP 9.5 reactive neuronal structures were significantly decreased in all layers of sigmoid colon specimens in patients with slow-transit constipation and acquired megacolon, compared with that of the control group. However, there was no statistically significant difference in either the density of ICC or that of neuronal structures between the patients with slow-transit constipation and acquired megacolon.

CONCLUSIONS

Slow-transit constipation and acquired megacolon were associated with alteration of ICC and neuronal cells of ENS in the sigmoid colon.

Human enteric neuropathies: morphology and molecular pathology

The aim of this study is to review current understanding of the molecular and morphological pathology of the enteric neuropathies affecting motor function of the human gastrointestinal tract and to evaluate the described pathological entities in the literature to assess whether a new nosology may be proposed. The authors used PUBMED and MEDLINE searches to explore the literature pertinent to the molecular events and pathology of gastrointestinal motility disorders including achalasia, gastroparesis, intestinal pseudo-obstruction, colonic inertia and megacolon in order to characterize the disorders attributable to enteric gut neuropathies. This scholarly review has shown that the pathological features are not readily associated with clinical features, making it difficult for a patient to be classified into any specific category. Individual patients may manifest more than one of the morphological and molecular abnormalities that include: aganglionosis, neuronal intranuclear inclusions and apoptosis, neural degeneration, intestinal neuronal dysplasia, neuronal hyperplasia and ganglioneuromas, mitochondrial dysfunction (syndromic and non-syndromic), inflammatory neuropathies (caused by cellular or humoral immune mechanisms), neurotransmitter diseases and interstitial cell pathology. The pathology of enteric neuropathies requires further study before an effective nosology can be proposed. Carefully studied individual cases and small series provide the basic framework for standardizing the collection and histological evaluation of tissue obtained from such patients. Combined clinical and histopathological studies may facilitate the translation of basic science to the clinical management of patients with enteric neuropathies.

New insights into human enteric neuropathies

The functioning of enteric neuronal circuitries has been elucidated in the recent past. Evidence is now gathering to explain how dysfunction of the enteric nervous system (ENS) may lead to human gastrointestinal motor disorders. These conditions include achalasia, congenital hypertrophic pyloric stenosis, chronic intestinal pseudo-obstruction, Hirschsprung's disease, chronic idiopathic constipation, and probably irritable bowel syndrome. Degenerative, inflammatory and genetic mechanisms exert a critical role in ENS dysfunction underlying gut dysmotility. The study of the ENS abnormalities in gut dysmotility provides a framework to better understand the mechanisms involved in degeneration and neuronal loss and fosters the development of targeted therapeutic options.

Colonic motor activity in slow-transit idiopathic constipation as identified by 24-h pancolonic ambulatory manometry

Colorectal motor activity in slow-transit idiopathic constipation has not been fully evaluated under physiological conditions. The aim of this study was to evaluate colorectal motor activity in chronic idiopathic constipation using 24-h ambulant pancolonic manometry. Ten healthy volunteers (six females) 19-31 years of age, and eight females 25-46 years of age with slow-transit idiopathic constipation were studied. Motor activity was measured using two custom-made silicone-coated catheters, each with five solid-state pressure transducers. Bowel preparation or sedation was not used. Frequency of high-amplitude propagated contractions was reduced in chronic idiopathic constipation, median 1.9/24 h vs 6/24 h (P = 0.01). Contractile frequency of low-amplitude complexes was reduced throughout the colon in slow-transit idiopathic constipation (P < 0.0001). The interval between contractile complexes was reduced in the transverse colon and splenic flexure (P < 0.0001). This study demonstrates that colonic motor activity is abnormal in slow-transit idiopathic constipation; decreased motor activity leads to a reduction in propulsion of intraluminal contents.

Chronic idiopathic slow transit constipation: pathophysiology and management

OBJECTIVE

Patients with idiopathic slow-transit constipation comprise a small proportion of the total population complaining of constipation. The purpose of this review is to present an update of pathophysiology of this disorder and its application in clinical management.

METHODS

Medline was used to search English language articles published up to the end of September 2002 on the subject of slow-transit constipation.

RESULTS AND CONCLUSIONS

Patients with idiopathic slow-transit constipation can be divided into 2 subgroups: 1. patients with normal proximal gastrointestinal motility and with onset of constipation in connection with childbirth or pelvic surgery. This subgroup may benefit from consideration of surgical treatment; 2. patients who have a dysfunctional enteric nervous/neuroendocrine system and exhibit colonic dysmotility as part of a generalised gastrointestinal dysmotility. Surgical approach in this subgroup seems to be unhelpful and medical treatment appears to be a better approach.

Study of the role of the second defecation reflex: anorectal excitatory reflex in the pathogenesis of constipation

BACKGROUND

Previous studies have shown that anal distension caused rectal contraction, an action mediated through the anorectal excitatory reflex. Anal anesthetization aborted rectal contraction and rectal evacuation was induced by excessive straining. We investigated the hypothesis that inhibition or absence of the anorectal excitatory reflex could lead to constipation.

METHODS

We studied 18 patients (mean age +/- SD: 40.6 +/- 5.8 years, 14 women) with rectal inertia, 14 (41.7 +/- 6.6 years, 12 women) with puborectalis paradoxical syndrome, and 10 healthy volunteers (37.9 +/- 4.8 years, 8 women). The rectum was filled with normal saline until urge and then evacuated; residual fluid was calculated. The anal and rectal pressure response to anal balloon distension in increments of 2 mL of saline was recorded by a two-channel microtip catheter.

RESULTS

In the healthy volunteers, saline was evacuated as a continuous stream without straining except occasionally at the start of evacuation; no residual fluid was encountered. Anal balloon distension effected notable rectal pressure increase. In rectal inertia patients, evacuation occurred in small fluid gushes produced with excessive straining; residual fluid of large volume was collected. Anal balloon distension up to 10 mL produced no notable rectal pressure changes. The patients with PPS failed to evacuate more than a few mL of fluid despite excessive straining; the volume of residual fluid was considerable. Anal balloon distension caused a notable rectal pressure rise. The results were reproducible.

CONCLUSIONS

These results suggest that the defecation reflexes (rectoanal and anorectal) are absent in rectal inertia patients and this presumably denotes a neurogenic disorder. The anorectal reflex is active in puborectalis paradoxical syndrome, but the rectoanal reflex is not, indicating a possible myogenic defect in the puborectalis muscle.

Enteric nerves and interstitial cells of Cajal are altered in patients with slow-transit constipation and megacolon

BACKGROUND & AIMS

A variety of gastrointestinal motility disorders have been attributed to alterations of interstitial cells of Cajal and malformations of the enteric nervous system. This study evaluates both the distribution of interstitial cells of Cajal and the pathohistology of the enteric nervous system in 2 severe human colorectal motility disorders.

METHODS

Colonic specimens obtained from patients with slow-transit constipation (n = 11), patients with megacolon (n = 6), and a control group (n = 13, nonobstructing neoplasia) were stained with antibodies against c-kit (marker for interstitial cells of Cajal) and protein gene product 9.5 (neuronal marker). The morphometric analysis of interstitial cells of Cajal included the separate registration of the number and process length within the different regions of the muscularis propria. The structural architecture of the enteric nervous system was assessed on microdissected whole-mount preparations.

RESULTS

In patients with slow-transit constipation, the number of interstitial cells of Cajal was significantly decreased in all layers except the outer longitudinal muscle layer. The myenteric plexus showed a reduced ganglionic density and size (moderate hypoganglionosis) compared with the control group. Patients with megacolon were characterized by a substantial decrease in both the number and the process length of interstitial cells of Cajal. The myenteric plexus exhibited either complete aganglionosis or severe hypoganglionosis.

CONCLUSIONS

The enteric nervous system and interstitial cells of Cajal are altered concomitantly in slow-transit constipation and megacolon and may play a crucial role in the pathophysiology of colorectal motility disorders.

Study of the motile activity of the colon in rectal inertia constipation

BACKGROUND

We have recently demonstrated that rectal distension effected left colonic contraction, which probably acts to feed the rectum with fecal matter each time the rectum distends and evacuates its contents. This effect was postulated to occur through the recto-colic reflex. As the colonic status in rectal inertia constipation was scarcely addressed in the literature, we investigated this point.

METHODS

The response of the colonic pressure to rectal balloon distension in increments of 10 mL of water was studied in 38 patients with rectal inertia constipation (IC) (age 42.6 +/- 14.3 years, 29 women) and 12 healthy volunteers (40.9 +/- 12.2 years, nine women). The rectal and colonic pressures were measured by saline-perfused tubes connected to a pneumohydraulic infusion system. The rectum was distended by a condom applied to the end of a 10-F catheter.

RESULTS

The rectal and left colonic resting pressures were significantly lower in the patients than in the controls (P < 0.5, P < 0.05, respectively). In the healthy volunteers, rectal distension up to first rectal sensation produced no significant rectal or colonic pressure changes (P > 0.05, P > 0.05). At urge, rectal and left colonic pressures increased significantly (P < 0.001, P < 0.001, respectively), but there were no changes in the right colonic pressure (P > 0.05). The colonic response lasted as long as the rectum was distended. In IC, patients did not perceive the first rectal or urge sensation up to a rectal balloon filling of 300 mL; there was no rectal or colonic pressure response (P > 0.05, P > 0.05).

CONCLUSION

In normal subjects, left colonic contraction on rectal distension probably acts to feed the rectum with fecal material. In IC, the low left colonic resting pressure assumedly points to left colonic hypotonia which appears to aggravate the constipation produced by the inertic rectum. Furthermore, non-response of the left colon to rectal distension probably impedes rectal feeding with fecal matter and enhances constipation.

Enteric nervous system disorders: genetic and molecular insights for the neurogastroenterologist

The goals of this review are to summarize some of the novel observations on the genetic and molecular basis of enteric nervous system disorders, with particular emphasis on the relevance of these observations to the practicing neurogastroenterologist. In the last two decades, there has been a greater understanding of genetic loci involved in congenital forms of pseudo-obstruction and Hirschsprung's disease; and the contribution of endothelins and nuclear transcription factors to the development of the enteric nervous system. In addition, clarification of the molecules involved in the activation of the peristaltic reflex, the disorders of the interstitial cells of Cajal, the clinical manifestations of mitochondrial cytopathies affecting the gut, and the application of neurotrophic factors for disorders of colonic function have impacted on practical management of patients with gut dysmotility.

Smooth muscle inclusion bodies in slow transit constipation

Slow transit constipation (STC) is a disorder of intestinal motility of unknown aetiology. Myopathies, including those characterized by the finding of inclusion bodies, have been described in enteric disorders. Amphophilic inclusion bodies have been reported in the muscularis externa of the colon of STC patients. This study formally tested the hypothesis that these represent a primary muscle disorder, specific to STC. In a systematic, blinded, dual observer qualitative and quantitative analysis, colonic and ileal tissue from patients with STC (n=36) were compared with selected control populations: total colonic aganglionosis (n=10), Chagas' disease (n=6), isolated rectal evacuation disorders (n=6), and a control population of a range of ages (n=80). All sections were stained with haematoxylin and eosin and periodic acid Schiff. Further immunostains were used in an attempt to determine inclusion body composition. Round or ovoid (4-22 microm diameter) amphophilic inclusions increased in number in normal subjects with age. Inclusions were more frequent in idiopathic STC than in age-matched controls or rectal evacuation disorders [ileum (33% vs. 9%), ascending (50% vs. 19%, p<0.05), and sigmoid colon (43% vs. 20%)] and were very frequent in the sigmoid (71%) of patients with STC arising after pelvic surgery. The number of inclusions per unit area was significantly higher in patients with STC (p<0.001). Inclusions were found in all Chagas' patients, but not with aganglionosis. It was not possible to determine inclusion body composition, despite the use of a wide range of conventional and immunostains. This study demonstrates that inclusion body myopathy is identifiable in patients with STC and that it may arise secondary to denervation.

Clinical and physiological heterogeneity in slow transit constipation: a review of 122 patients

OBJECTIVE

The outcome of surgery in patients with slow transit constipation (STC) is unpredictable. This may reflect clinical and physiological heterogeneity within this group of patients. This study attempts to identify subgroups of patients with STC according to clinical history, and compares the pathophysiological findings between the two largest: including patients with chronic idiopathic STC, and those with symptoms acquired after pelvic surgery or childbirth (post-pelvic intervention STC).

PATIENTS AND METHODS

Review of clinical and gastrointestinal pathophysiological findings of 122 consecutive patients with slow colonic transit.

RESULTS

Six subgroups of patients were defined according to the time and nature of onset of symptoms. Pathophysiological comparison of the two main groups: chronic idiopathic STC (n=65 (53%)) and post-pelvic intervention STC (n=22 (18%)), yielded three main conclusions: (i) the pattern of colonic transit is similar in both groups, i.e. predominantly (approximately 70%) generalized; (ii) the prevalence of a rectal evacuatory disorder is significantly higher in patients with post-pelvic intervention STC (77% vs 32%, P=0.004); and (iii) small bowel motility disturbances occur in both groups (overall 48%), and are therefore not limited to patients with chronic idiopathic STC.

CONCLUSION

There are pathophysiological similarities and differences between the main two subgroups of STC. Such findings may help our understanding of the pathogenesis and have implications in the future management of these patients.

Idiopathic slow-transit constipation is not associated with mutations of the RET proto-oncogene or GDNF

PURPOSE

Idiopathic slow-transit constipation is a severe disorder of unknown cause. The onset in early childhood and history of constipation or Hirschsprung's disease in close family relatives suggest that slow-transit constipation could have a genetic basis. Several germline mutations have been described in Hirschsprung's disease, including mutations of RET and the gene encoding its ligand glial cell-derived neurotrophic factor. The aim of this study was to screen a panel of 16 cases of familial idiopathic slow-transit constipation, including 4 families in which there were relatives with Hirschsprung's disease, for RET and glial cell-derived neurotrophic factor mutations previously identified in Hirschsprung's disease.

METHODS

Genomic DNA from 16 patients with slow-transit constipation and four relatives with Hirschsprung's disease was analyzed using single strand and heteroduplex conformation polymorphism analysis at two conditions and by direct DNA sequencing using the fluorescent dideoxy terminator method.

RESULTS

Although common sequence polymorphisms were demonstrated with a frequency comparable with published data, no published or new mutation was seen in any of the exons of RET or glial cell-derived neurotrophic factor.

CONCLUSIONS

Mutation of RET or glial cell-derived neurotrophic factor is not a frequent cause of idiopathic slow-transit constipation.

Interstitial cells of Cajal in slow transit constipation and megabowel

OBJECTIVE

Disordered gut motor activity is a feature of patients with chronic idiopathic constipation. Interstitial cells of Cajal (ICC) are thought to modulate gut motility. The aim of this study was to test the hypothesis that there is an abnormality of the density of distribution of ICC in slow transit constipation and megabowel.

PATIENTS AND METHODS

ICC were identified by immunohistochemistry using an anti-c-kit antibody. Six patients (slow transit constipation n=3; megabowel n=3) were compared with normal controls. The density of distribution of ICC was assessed in the longitudinal and circular muscle layers, and in the intermuscular plane of the colon. Statistical analysis was performed using Fisher's exact test and χ(2) test.

RESULTS

No consistent pattern of difference in the density of ICC could be identified between the constipated and control groups.

CONCLUSION

The density of ICC in the constipated patients was not significantly different from normal colon. The results in these patients suggest that if ICC have a role in the causation of slow transit idiopathic constipation or megabowel then an abnormality of function rather than distribution is implicated.

Slow transit constipation: a model of human gut dysmotility. Review of possible aetiologies

Slow transit constipation is a severe condition of gut dysmotility that predominantly affects young women and may result in surgical intervention. Current medical treatments for STC are often ineffective, and the outcome of surgery is unpredictable. STC was first described almost a century ago. Since this time, progress in improving therapy for this condition has been complicated by a lack of understanding of the aetiology, and great variation in the methods and criteria used for the study of patients with this debilitating disorder. It is difficult to find unequivocal data, and harder still to give a definitive picture of the cause or causes of STC. Here we consider the evidence for various aetiologies of STC, in the light of the physiological and pathological findings.

Constipation, diarrhea, and irritable bowel syndrome

Constipation, diarrhea, and irritable bowel syndrome are commonly encountered in the primary care practice. Most episodes of constipation and diarrhea are benign and self-limited. Patients with chronic constipation should undergo a screening evaluation to exclude organic disease, after which most can be managed successfully with dietary modification and fiber supplementation. The cause of chronic diarrhea usually can be discerned clinically, with irritable bowel syndrome, inflammatory bowel disease, and lactose intolerance being diagnosed most frequently. Irritable bowel syndrome is a functional gastrointestinal disorder characterized by abdominal pain and disordered defecation, which is successfully managed with a strong physician-patient relationship and periodic pharmacologic intervention.

Sensory and autonomic neuropathy in patients with idiopathic slow-transit constipation

BACKGROUND

Slow-transit constipation (STC) is a severe disorder of unknown aetiology, which may result from an autonomic or sensory neuropathy. This study aimed to investigate patients with STC for the presence of neural dysfunction, and relate the findings to other factors, including any familial associations.

METHODS

Thirty-three patients with STC were studied using standard neurophysiological tests and a range of quantitative sensory and autonomic tests. The findings were compared with those of 20 matched control subjects and nine diabetic patients with gastrointestinal symptoms.

RESULTS

Twenty of the 33 patients with STC gave a family history of constipation, including an affected identical twin and Hirschsprung's disease (n = 3). None had abnormalities on neurological examination or nerve conduction studies. Fifteen of the 33 patients had abnormalities on quantitative tests, including all six who required a colectomy. Eleven patients with STC had reduced axon-reflex sweating in the presence of normal sweat gland responses (P < 0.001, all patients with STC versus controls). Twelve patients with STC had small sensory fibre dysfunction, with significantly increased thermal thresholds (cool, P < 0.05; warm, P < 0.01); these included six of nine patients with STC and rectal hyposensation. There were similar findings on quantitative testing in diabetic patients.

CONCLUSION

Quantitative tests in patients with STC provide evidence of a small fibre neuropathy. The high incidence of a positive family history, particularly a possible association with Hirschsprung's disease, suggests a genetic basis, which deserves further investigation.

Cholinergic stimulation and nonadrenergic, noncholinergic relaxation of human colonic circular muscle in idiopathic chronic constipation

The aim of our study was to further investigate the pathophysiological mechanism underlying idiopathic chronic constipation (ICC), a disorder of colonic motility. A possible alteration of excitatory and inhibitory neurotransmission and also the role of inhibitory neurotransmitters such as nitric oxide (NO), 5'-adenosine triphosphate (ATP), and vasoactive intestinal peptide (VIP) has been evaluated on preparations of distal colon from patients with or without ICC. The isometric tension was recorded from isolated circular muscle strips of both experimental groups during pharmacological and electrical field stimulation (EFS). The contractile response obtained by acetylcholine (ACh 20 microM), EFS (20 Hz, 20 V, 1 msec, pulse trains lasting 1 min) and substance P (SP 1 microM) was significantly lower in ICC than in control preparations. The effect of inhibitory nonadrenergic, noncholinergic innervation was evaluated using EFS at low frequencies (0.5-8 Hz), after cholinergic and sympathetic blockade with atropine (3 microM) and guanethidine (3 microM). The maximum relaxation value expressed as percentage of inhibition of SP-induced contraction was significantly higher in ICC than in control preparations (87+/-2.4 and 67+/-6.3, respectively; P<0.05). Experiments with substances that antagonize or reduce the effect of putative inhibitory mediators (VIP 6-28, apamin and N(G)-nitro-L-arginine) suggest that an alteration in NO and ATP release is present in ICC preparations. In particular at a higher inhibitory frequency NO-mediated relaxation is enhanced in ICC vs control, supporting the hypothesis that excessive NO production may be involved in pathophysiological mechanism of constipation.

Quantitative analysis of nerve changes in the lateral retinaculum in patients with isolated symptomatic patellofemoral malalignment. A preliminary study

Neural damage in 16 lateral retinacula excised at the time of Insall proximal realignments or isolated lateral retinacular releases performed in patients with symptomatic patellofemoral malalignment was evaluated by means of conventional histology and immunohistochemical and morphometric analyses. A relationship between clinical and histologic findings was found. An increase in the proportion of innervated tissue was correlated with anterior knee pain syndrome. We found a significant relationship between total neural area and pain. The group with moderate pain had the highest number of nerves and the highest neural area. In reference to total neural area and pain, there was a significant difference only between the patients with moderate pain and those with light pain, but not between patients with severe pain and those with moderate pain. The group with severe pain also showed a high neural area, although with a lower number of nerves. The severe-pain group had the largest nerves (24% of nerve fibers surpassing 25 microns diameter) in a zonal disposition, in which there were groups of nerve fibers in some fields and no nerve fibers in others. The group with moderate pain had an increase in medium and small nerve fibers (mean diameter, 18 microns), predominantly of tiny perivascular fibers. Moreover, we believe that instability in patients with patellofemoral malalignment can be explained in part because of loss of proprioception due to neural damage.