Slow transit chronic constipation (Arbuthnot Lane's disease). An immunohistochemical study of neuropeptide-containing nerves in resected specimens from the large bowel

Constipation Caused by Anti-calcitonin Gene-Related Peptide Migraine Therapeutics Explained by Antagonism of Calcitonin Gene-Related Peptide's Motor-Stimulating and Prosecretory Function in the Intestine

The development of small-molecule calcitonin gene-related peptide (CGRP) receptor antagonists (gepants) and of monoclonal antibodies targeting the CGRP system has been a major advance in the management of migraine. In the randomized controlled trials before regulatory approval, the safety of these anti-CGRP migraine therapeutics was considered favorable and to stay within the expected profile. Post-approval real-world surveys reveal, however, constipation to be a major adverse event which may affect more than 50% of patients treated with erenumab (an antibody targeting the CGRP receptor), fremanezumab or galcanezumab (antibodies targeting CGRP). In this review article we address the question whether constipation caused by inhibition of CGRP signaling can be mechanistically deduced from the known pharmacological actions and pathophysiological implications of CGRP in the digestive tract. CGRP in the gut is expressed by two distinct neuronal populations: extrinsic primary afferent nerve fibers and distinct neurons of the intrinsic enteric nervous system. In particular, CGRP is a major messenger of enteric sensory neurons which in response to mucosal stimulation activate both ascending excitatory and descending inhibitory neuronal pathways that enable propulsive (peristaltic) motor activity to take place. In addition, CGRP is able to stimulate ion and water secretion into the intestinal lumen. The motor-stimulating and prosecretory actions of CGRP combine in accelerating intestinal transit, an activity profile that has been confirmed by the ability of CGRP to induce diarrhea in mice, dogs and humans. We therefore conclude that the constipation elicited by antibodies targeting CGRP or its receptor results from interference with the physiological function of CGRP in the small and large intestine in which it contributes to the maintenance of peristaltic motor activity, ion and water secretion and intestinal transit.

Preventive Effect of Lactobacillus fermentum Zhao on Activated Carbon-Induced Constipation in Mice

The aim of this study was to investigate the effects of Lactobacillus fermentum Zhao (LF-Zhao) on activated carbon-induced constipation in ICR mice. ICR mice were administered lactic acid bacteria by gavage for 9 d. Body weight, diet intake, drinking amount, stool status, gastrointestinal transit distance and stool time, in addition to motilin (MTL), gastrin (Gas), endothelin (ET), somatostatin (SS), acetylcholinesterase (AChE), substance P (SP) and vasoactive intestinal peptide (VIP) levels in serum were monitored to evaluate the preventive effects of LF-Zhao on constipation. Bisacodyl, a laxative drug, was used as a positive control. Times to the first black stool for normal (untreated), control (no lactic acid bacteria treatment but activated carbon treated), bisacodyl-treated and L. delbrueckii subsp. bulgaricus (LB), LF-Zhao (L) (low concentration of 1×10(8) CFU/mL)- and LF-Zhao (H) (high concentration of 1×10(9) CFU/mL)-treated mice induced by activated carbon were 90, 218, 117, 180, 169 and 156 min, respectively. Following the consumption of LB, LF-Zhao (L) and LF-Zhao (H) or the oral administration of bisacodyl, the gastrointestinal transit distances were reduced by 55.2%, 61.3%, 70.6% and 94.6%, respectively. The serum levels of MTL, Gas, ET, AChE, SP and VIP were significantly increased and the serum levels of SS were reduced in the mice treated with LF-Zhao compared with those in the control mice (p<0.05). These results demonstrated that lactic acid bacteria demonstrate preventive effects on mouse constipation and that LF-Zhao alleviated constipation symptoms better than LB.

Opioid receptors and associated regulator of G protein signaling are involved in the cathartic colon of rats

A cathartic colon is characteristic of slow transit constipation (STC), which can result following the long-term use of irritant laxatives. In the present study, the involvement of three opioid receptor subtypes (μ, MOR; δ, DOR; and κ, KOR), regulator of G protein signaling 4 (RGS-4) and β-arrestin-2 were investigated in the cathartic colon of rats. A rat model of a cathartic colon was established by feeding the animals with phenolphthalein, while normal rats were used as a control. The mRNA and protein expression levels of the opioid receptors, RGS-4 and β-arrestin-2 were detected in the rat colon using semi-quantitative reverse transcription polymerase chain reaction and western blot analysis, respectively. The rat model of a cathartic colon was successfully established using the phenolphthalein stimulus, and was shown to result in shrunken myenteric neurons and loose muscle fibers in the intestinal wall. The mRNA and protein expression levels of the three opioid receptor subtypes, RGS-4 and β-arrestin-2 were significantly higher in the cathartic colon group when compared with the levels in the normal control group (all P<0.01). With regard to the protein expression levels, MOR protein increased 2.4 fold, DOR expression increased 1.5 fold, KOR levels increased 1.5 fold, RGS-4 protein increased 3.5 fold and β-arrestin-2 expression increased 2.0 fold. Therefore, the expression levels of opioid receptors were found to increase in the cathartic colons of the rats, indicating that opioid receptors and downstream RGS-4 and β-arrestin-2 signaling may play an important role in the pathogenesis of STC.

Preventive effect of Lactobacillus fermentum Lee on activated carbon-induced constipation in mice

The aim of this study was to investigate the effects of Lactobacillus fermentum Lee (LF-Lee) on activated carbon-induced constipation in ICR mice. ICR mice were orally administered lactic acid bacteria for nine days. Body weight, dietary and water intake, defecation status, gastrointestinal (GI) transit and defecation time, as well as levels of motilin (MTL), gastrin (Gas), endothelin (ET), somatostatin (SS), acetylcholinesterase (AChE), substance P (SP) and vasoactive intestinal peptide (VIP) in serum were measured to evaluate the preventive effects of LF-Lee on constipation. Bisacodyl, a laxative drug, was administered as a positive control. The time taken until the first defecation of a black stool for normal, control, bisacodyl- (100 mg/kg, oral administration), Lactobacillus bulgaricus (LB)-, LF-Lee low dose (L)- and LF-Lee high dose (H)-treated mice was 90, 218, 117, 180, 161 and 151 min, respectively. Following the consumption of LB, LF-Lee (L) or LF-Lee (H), or the oral administration of bisacodyl, the GI transit was reduced to 55.2, 65.8, 73.1 and 94.6%, respectively, of the transit in normal mice. The serum levels of MTL, Gas, ET, AChE, SP and VIP were significantly increased and those of SS were reduced in the mice treated with LF-Lee compared with those in the untreated control mice (P<0.05). These results demonstrate that lactic acid bacteria have preventive effects on constipation in mice and that LF-Lee has superior functional activity.

Preventive effect of resistant starch on activated carbon-induced constipation in mice

The aim of this study was to investigate the effects of resistant starch (RS) on activated carbon-induced constipation in ICR mice. ICR mice were fed on diet containing 15% RS of type RS2, RS3 or RS4 for 9 days. Gastrointestinal transit, defecation time and intestinal tissue histopathological sections, as well as motilin (MTL), gastrin (Gas), endothelin (ET), somatostatin (SS), acetylcholinesterase (AChE), substance P (SP) and vasoactive intestinal peptide (VIP) levels in serum were used to evaluate the preventive effects of RS on constipation. Bisacodyl, a laxative drug, was used as a positive control. The time to the first black stool defecation for normal, control, bisacodyl-treated (100 mg/kg, oral administration) and RS2-, RS3- and RS4-treated mice was 78, 208, 109, 181, 144 and 173 min, respectively. Following the consumption of RS2, RS3 and RS4 or the oral administration of bisacodyl (100 mg/kg), the gastrointestinal transit was reduced to 37.7, 52.1, 39.3 and 87.3%, respectively, of the transit in normal mice, respectively. Histopathological sections of intestinal tissue also underscored the protective effect of RS3. The serum levels of MTL, Gas, ET, AChE, SP and VIP were significantly increased and the serum levels of SS were reduced in the mice treated with RS compared with those in the untreated control mice (P<0.05). These results demonstrate that RS has preventive effects on mouse constipation and RS3 demonstrated the best functional activity.

'Idiopathic' intestinal failure--the importance of identifying and treating primary psychopathology

BACKGROUND

Gastrointestinal neuromuscular disorders (GINMD) are an important cause of intestinal failure (IF). We present six cases of IF in whom a diagnosis of GINMD was initially suspected, but in whom psychopathology was discovered to be the primary etiology.

METHODS

(i) Six consecutive cases referred to our unit with IF, initially presumed to be due to GINMD, were selected. Informed consent was obtained from all patients. Case notes were reviewed for salient clinical information. (ii) A literature search was performed to ascertain the epidemiology of psychopathology in IF and the current evidence for the management of severe functional GI disorders with a multidisciplinary psychiatric approach.

KEY RESULTS

(i)All six cases required multidisciplinary psychiatric management in a specialized psychiatric unit that included the use of antidepressants, antipsychotics, mood stabilizers, and Electroconvulsive therapy in addition to nutritional support via enteral or parenteral routes. (ii) The evidence base for the treatment of severe FGIDs is sparse.

CONCLUSIONS & INFERENCES

There is a need for additional reporting of such cases and further research. Our experience would suggest that a delay in the involvement of a specialist liaison psychiatrist has the potential to be life threatening in such cases. This may be more likely with greater severity, where the apparent predominance of 'physical' symptoms generates reluctance in both patient and physician to consider a psychiatric etiology and also appears to occur due to a lengthier investigative process than existed previously. We therefore propose that the provision of a specialist psychiatric assessment for all patients presenting with IF is indicated at the point of initial clinical contact, based upon the substantial clinical benefit it has the potential to confer upon a significant minority. This process need not delay investigation, which can continue as indicated in parallel, but can be life-saving.

Progesterone receptors and serotonin levels in colon epithelial cells from females with slow transit constipation

BACKGROUND

Females with slow transit constipation (STC) exhibit progesterone receptor (P4R) overexpression in colon muscle that impair their contractility. These studies examined whether these patients have an overexpression of P4R in epithelial cells and whether P4 affects the SERT-5-HT pathway.

METHODS

Tissues were obtained from surgical specimens of seven females with STC and six controls. Feasibility studies were performed in biopsies from six patients with STC and three controls. P4R, SERT and TPH-1 mRNA and protein expression and 5-HT by ELISA were determined. Contraction was studied in normal muscle cells pretreated with P4 or buffer. Progesterone effects on SERT and 5-HT levels were studied in normal human mucosa in vitro and in wild and SERT knockout mice in vivo.

KEY RESULTS

P4R was overexpressed in epithelial cells in STC compared with controls. The levels of SERT were lower and 5-HT higher in STC. In epithelial cells P4 treatment decreased SERT and increased mucosal 5-HT without affecting TPH-1. Progesterone impaired the contraction of normal muscle cells induced by Ach and 5-HT. Progesterone decreased SERT and increased 5-HT levels in the colon of wild mice in vivo but had no effect on the high basal levels of 5-HT in SERT knockout mice.

CONCLUSIONS & INFERENCES

P4R are present in colon epithelial cells and are overexpressed in females with STC. These cells have reduced SERT and high 5-HT levels and normal TPH-1. These 5-HT signaling abnormalities are related to overexpression of P4R since they are reproduced in human epithelial cells in vitro and in mice in vivo.

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.

Cyclooxygenase-dependent alterations in substance P-mediated contractility and tachykinin NK1 receptor expression in the colonic circular muscle of patients with slow transit constipation

Tachykinins are important neurotransmitters regulating intestinal motility. Slow transit constipation (STC) represents an extreme colonic dysmotility with unknown etiology that predominantly affects women. We examined whether the tachykinin system is involved in the pathogenesis of STC. Isolated sigmoid colon circular muscle from female STC and control patients was studied using functional and quantitative reverse transcriptase-polymerase chain reaction methods. A possible alteration of neurotransmission was investigated by electrical field stimulation (EFS) and ganglionic stimulation by dimethylphenylpiperazinium (DMPP). Substance P (SP)-mediated contractions in circular muscle strips were significantly diminished in STC compared with age-matched control (P < 0.001). In contrast, contractile responses to neurokinin A, the selective tachykinin NK(2) receptor agonist, [Lys(5),MeLeu(9),Nle(10)]NKA(4-10), and acetylcholine were unaltered in STC. The reduced responses to SP in STC were fully restored by indomethacin, partially reversed by tetrodotoxin (TTX), but unaffected by atropine or hexamethonium. The restoration by indomethacin was blocked by the NK(1) receptor antagonist CP99994 [(2S,3S)-3-(2-methoxybenzylamino)-2-phenylpiperidine] and TTX. In STC colonic muscle, there was a significant increase of NK(1) receptor mRNA expression, but no difference in NK(2) mRNA level. DMPP generated biphasic responses, relaxation at lower and contraction at higher concentrations. Although the responses to DMPP were similar in STC and control, an altered contractile pattern in response to EFS was observed in STC circular muscle. In conclusion, we postulate that the diminished contractile response to SP in STC is due to an increased release of inhibitory prostaglandins through activation of up-regulated NK(1) receptors. Our results also indicate some malfunction of the enteric nervous system in STC.

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.

Enteric neurodegeneration in ageing

The objective of this article is to review the clinical presentation and neurobiology of degeneration of the enteric nervous system with emphasis on human data where available. Constipation, incontinence and evacuation disorders are frequently encountered in the ageing population. Healthy lower gastrointestinal function is essential for successful ageing as it is critical to maintaining independence and autonomy to pursue further activity. One clinical expression of enteric neurodegeneration is constipation. However, the aetiology may be multifactorial as disturbances of epithelial, muscle or neural function may all result from neurodegeneration. There is evidence of loss of excitatory (e.g. cholinergic) enteric neurons and interstitial cells of Cajal, whereas inhibitory (including nitrergic) neurons appear unaffected. Understanding neurodegeneration in the enteric nervous system is key to developing treatments to reverse it. Neurotrophins have been shown to accelerate colonic transit and relieve constipation in the medium term; they are also implicated in maintenance programmes in adult enteric neurons through a role in antioxidant defence. However, their effects in ageing colon require further study. There is evidence that 5-HT(2) and 5-HT(4) mechanisms are involved in development, maintenance and survival of enteric neurons. Further research is needed to understand and potentially reverse enteric neurodegeneration.

Enteric neurodegeneration in ageing

The objective of this article is to review the clinical presentation and neurobiology of degeneration of the enteric nervous system with emphasis on human data where available. Constipation, incontinence and evacuation disorders are frequently encountered in the ageing population. Healthy lower gastrointestinal function is essential for successful ageing as it is critical to maintaining independence and autonomy to pursue further activity. One clinical expression of enteric neurodegeneration is constipation. However, the aetiology may be multifactorial as disturbances of epithelial, muscle or neural function may all result from neurodegeneration. There is evidence of loss of excitatory (e.g. cholinergic) enteric neurons and interstitial cells of Cajal, whereas inhibitory (including nitrergic) neurons appear unaffected. Understanding neurodegeneration in the enteric nervous system is key to developing treatments to reverse it. Neurotrophins have been shown to accelerate colonic transit and relieve constipation in the medium term; they are also implicated in maintenance programmes in adult enteric neurons through a role in antioxidant defence. However, their effects in ageing colon require further study. There is evidence that 5-HT(2) and 5-HT(4) mechanisms are involved in development, maintenance and survival of enteric neurons. Further research is needed to understand and potentially reverse enteric neurodegeneration.

Evolution of the restorative proctocolectomy and its effects on gastrointestinal hormones

Gastrointestinal (GI) peptide hormones are chemical messengers that regulate secretory, mechanical, metabolic, and trophic functions of the gut. Restorative proctocolectomy (RPC) or resection of the colon and rectum with maintenance of intestinal continuity through the construction of an ileal pouch reservoir and preservation of the anal sphincters has become the standard of care for the surgical treatment of ulcerative colitis and familial adenomatous polyposis. The manipulation of the digestive system to create the ileal pouch involves altering gut-associated lymphoid tissue among other anatomic changes that lead to changes in GI peptides. In addition, the ileal pouch epithelium responds to a wide variety of stimuli by adjusting its cellularity and function. These adaptive mechanisms involve systemic factors, such as humoral and neural stimuli, as well as local factors, such as changes in intestinal peristalsis and intraluminal nutrients. There have been conflicting reports as to whether the alterations in GI hormones after RPC have actual clinical implications. What the studies on alterations of GI peptides' response and behavior after RPC have contributed, however, is a window into the possible etiology of complications after pouch surgery, such as pouchitis and malabsorption. Given the possibility of pharmacologically modifying GI peptides or select components of adaptation as a therapeutic strategy for patients with ileal pouch dysfunction or pouchitis, a clear understanding of human pouch mucosal adaptation is of paramount importance. In this review, we summarize the evolution of the RPC and its effects on the GI hormones as well as their possible clinical implications.

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.

Opioid-induced gastrointestinal dysfunction

Use of opioid analgesics is associated with a number of side effects, especially opioid-induced gastrointestinal dysfunction. The extensive use of these compounds and the significant negative impact of the resulting gastrointestinal dysfunction on patients' quality of life make it an important clinical issue. In recent years our understanding of the mechanisms of opioid-induced gastrointestinal dysfunction has advanced greatly. This article reviews the underlying pathophysiological mechanisms of specific gastrointestinal adverse effects of opioids. The role of endogenous opioid peptides in certain gastrointestinal diseases is also discussed. A better understanding of the pathophysiological mechanisms of opioid-induced bowel dysfunction should lead to the development of newer opioid analgesics and improved regimens resulting in reduced gastrointestinal adverse effects.

Colonic manometry via appendicostomy shows reduced frequency, amplitude, and length of propagating sequences in children with slow-transit constipation

BACKGROUND/PURPOSE

We wish to define colonic motor function in children with slow-transit constipation (STC) using manometry catheters introduced through appendiceal stomas, previously sited for controlling fecal retention by colonic irrigation.

METHODS

We undertook 24-hour pancolonic manometry of 6 children (5 boys; mean, 11.5 years; SD, 3.0) using a multilumen silastic catheter.

RESULTS

were compared to nasocolonic motility studies obtained in healthy young adults.

RESULTS

Antegrade propagating sequences (APSs) originated less frequently in the cecum compared to controls. There were fewer APS (mean +/- SEM: STC, 13 +/- 6 per 24 hours; controls, 52 +/- 6 per 24 hours; P < .01) and high-amplitude propagating contractions (HAPCs: STC, 5 +/- 2 per 24 hours; controls, 9.9 +/- 1.4 per 24 hours; P < .05). The amplitude of APS and HAPC was less in STC (APS, 39 +/- 9 mm Hg; controls, 54 +/- 3 per 24 hours; P < .05) (HAPC: STC, 94 +/- 10 mm Hg; control, 117 +/- 3 mm Hg; P < .01), whereas the amplitude of retrograde propagating sequences was greater in STC (43 +/- 6 mm Hg; control, 27 +/- 1 mm Hg; P < .01). The distances propagated by HAPC were significantly less in STC (36 +/- 4.5 vs 47 +/- 2.3 cm, controls; P < .05), and there was no evidence of a region-specific difference in propagation velocity of APS. Neither meal ingestion nor waking significantly increased colonic motor activity in patients with STC.

CONCLUSIONS

Despite the small numbers available to be studied, we found that children with STC in whom an appendicostomy had been placed show significant abnormalities in pancolonic motor function.

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.

Mortality, morbidity and functional outcome after ileorectal anastomosis

BACKGROUND

Total colectomy with an ileorectal anastomosis (IRA) is a commonly performed operation. Postoperative mortality and morbidity are reported to be low and functional outcome is generally rated as good to excellent. The aim of this study was to review postoperative mortality, morbidity and functional results in an effort to identify risk factors predictive of a poor outcome.

METHODS

Some 215 patients (118 women and 97 men) with a median age of 33 (interquartile range (i.q.r.) 25-47) years underwent an IRA between November 1990 and December 1999. Median follow-up was 2 years 9 months (i.q.r. 1-5 years). The clinical notes of these patients were reviewed retrospectively to analyse the postoperative course, bowel function and long-term clinical outcome.

RESULTS

The indications for surgery included familial adenomatous polyposis (52.1 per cent), Crohn's disease (14.4 per cent), functional bowel disorder (14.4 per cent), ulcerative colitis (8.4 per cent) and colonic carcinoma (4.7 per cent). The overall 30-day mortality and morbidity rates were 0.9 and 26.0 per cent respectively. This included anastomotic leak (6.5 per cent), small bowel obstruction (14.4 per cent), fistula (2.8 per cent) and anastomotic stricture (1.4 per cent). The incidence of fistula and anastomotic stricture was significantly higher in Crohn's disease (P < 0.001 and P = 0.005 respectively). Only 16 of 31 patients with Crohn's disease had a functioning IRA at long-term follow-up. Median stool frequency was 3 (i.q.r. 3-5) per day one year following surgery and did not change with longer follow-up.

CONCLUSION

Mortality and morbidity rates following IRA are low. Postoperative fistula and anastomotic stricture are more common in patients with Crohn's disease, approximately half of whom will eventually need a permanent ileostomy. Long-term bowel function for all groups is satisfactory.

Pan-colonic decrease in interstitial cells of Cajal in patients with slow transit constipation

BACKGROUND

Interstitial cells of Cajal (ICC) are required for normal intestinal motility. ICC are found throughout the human colon and are decreased in the sigmoid colon of patients with slow transit constipation.

AIMS

The aims of this study were to determine the normal distribution of ICC within the human colon and to determine if ICC are decreased throughout the colon in slow transit constipation.

PATIENTS

The caecum, ascending, transverse, and sigmoid colons from six patients with slow transit constipation and colonic tissue from patients with resected colon cancer were used for this study.

METHODS

ICC cells were identified with a polyclonal antibody to c-Kit, serial 0.5 microm sections were obtained by confocal microscopy, and three dimensional software was employed to reconstruct the entire thickness of the colonic muscularis propria and submucosa.

RESULTS

ICC were located within both the longitudinal and circular muscle layers. Two networks of ICC were identified, one in the myenteric plexus region and another, less defined network, in the submucosal border. Caecum, ascending colon, transverse colon, and sigmoid colon displayed similar ICC volumes. ICC volume was significantly lower in the slow transit constipation patients across all colonic regions.

CONCLUSIONS

The data suggest that ICC distribution is relatively uniform throughout the human colon and that decreased ICC volume is pan-colonic in idiopathic slow transit constipation.

Long-term results of subtotal colectomy for severe slow-transit constipation in patients with normal rectal function

OBJECTIVE

The outcome of subtotal colectomy for severe constipation may be difficult to predict. One factor, which probably is of major importance for the functional outcome, is rectal function. The aim of the study has been to evaluate long-term results after subtotal colectomy with ileo-rectal anastomosis in a group of patients with severe slow-transit constipation but without evidence of impaired rectal emptying.

PATIENTS AND METHODS

Of 273 patients with constipation referred for surgical evaluation 18 (7%) fulfilled our criteria for subtotal colectomy. Slow-transit was confirmed by radio-opaque marker studies and normal rectal function by emptying of viscous fluid and normal emptying at defecography.

RESULTS

At follow up between 3 and 9 years 15 patients had a bowel frequency between 2 and 6 daily. One patient, who had an ileostomy because of anastomotic leak, had not wanted bowel continuity restored. One patient with opiate abuse became less constipated with 2-3 bowel movements a week. One patient was still constipated one year after the operation and subsequently had an ileal pouch-anal anastomosis. This patient who had normal rectal emptying had a very high volume tolerability with a maximum tolerable volume of 700 ml. In 4 of 7 patients abdominal pain persisted after the operation, and 3 developed diarrhoea, which required daily intake of loperamide.

CONCLUSION

Subtotal colectomy for severe slow-transit constipation is justified provided anorectal function is normal. In spite of normal rectal emptying very high rectal volume tolerability may be an indicator of functional megarectum and impaired rectal emptying postoperatively.

Slow transit constipation in children

Patients with chronic constipation that fails to respond to treatment remain a challenge for paediatricians and surgeons. Ongoing work in our institution suggests that a number of children with intractable symptoms have slow transit constipation, which has only been described recently in paediatrics. Common features of slow transit are: delayed passage of the first meconium stool beyond 24 h of age, symptoms of severe constipation within a year, or treatment-resistant 'encopresis' at 2-3 years, soft stools despite infrequent bowel actions, and delay in colonic transit on a transit study. A proportion of children with slow transit constipation have an abnormality of intestinal innervation associated with the dysfunctional colonic motility, recognized as intestinal neuronal dysplasia (IND). Intestinal neuronal dysplasia type B, the most common variant of IND, is defined on rectal biopsy by hyperplasia of the submucosal plexus. On laparoscopic colon muscle biopsy, many specimens show reduced numbers of excitatory substance P-immunoreactive nerve fibres in the circular muscle. Functional markers of the nerves allow new diagnostic criteria to be developed which may also allow a more rational approach to treatment. The aetiology remains obscure and the optimal management poorly defined, although subtotal colectomy, proximal colostomy or appendicostomy (for antegrade enemas) have been tried. Once the anatomy and physiology of the colon in children with slow colonic transit is better understood, we will have defined not only a new form of constipation, but also will be able to consider new therapies.

Neurotransmitter coding of enteric neurones in the submucous plexus is changed in non-inflamed rectum of patients with Crohn's disease

Knowledge of the neurochemical coding of submucosal neurones in the human gut is important to assess neuronal changes under pathological conditions. We therefore investigated transmitter colocalization patterns in rectal submucosal neurones in normal tissue (n=11) and in noninflamed tissue of Crohn's disease (CD) patients (n=17). Neurone-specific enolase (NSE), choline acetyltransferase (ChAT), vasoactive intestinal polypeptide (VIP), substance P (SP), nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP) were detected immunohistochemically in whole-mount preparations from rectal biopsies. The neuronal marker NSE revealed no differences in the number of cells per ganglion (controls 5.0; CD 5.1). Four cell populations with distinct neurochemical codes were identified. The sizes of the populations ChAT/VIP (58% vs. 55%), ChAT/SP (8% vs. 8%), and ChAT/- (22% vs. 22%) were similar in control and CD. The population VIP/- was significantly increased in CD (12% vs. 2% in controls). Unlike in controls, all NOS neurones colocalized ChAT in CD. Thickened CGRP-fibres occurred in CD. We identified neurochemically distinct populations in the human submucous plexus. The increase in the VIP/- population, extensive colocalization of ChAT and NOS and hypertrophied CGRP fibres indicated adaptive changes in the enteric nervous system in noninflamed rectum of CD patients.

Gastrointestinal transit and anorectal manometry in children with colonic substance P deficiency

BACKGROUND AND AIMS

Severe intractable constipation in children may be associated with a reduction of substance P (SP)- containing fibers in colonic circular muscle. The aim of this study was to characterize gastrointestinal transit (GIT), anorectal manometry (ARM) and electromyographic (EMG) changes in these children.

METHODS

Seromuscular laparoscopic biopsies of the colon were obtained from 35 children with severe constipation. Immunofluorescent staining for SP and vasoactive intestinal peptide (VIP) were then performed on these specimens. The cohort of patients studied included a SP-deficient group (SPD, n = 25) who had reduced numbers of SP-immunoreactive nerve fibers. The other group consisted of patients with normal staining for both SP and VIP (SPN, n = 10). Gastrointestinal transit studies (gastric emptying, orocecal and colonic transit) suitable for analysis were available for 17 patients (SPD, n = 9 and SPN, n = 8). The colon was divided into segments and radioactivity counts in each segment were expressed as a percentage of the total colonic count at each time point (6, 24, 32 and 48 h). The geometric center (GC), ARM, EMG, clinical and demographic data characteristics of both groups of patients were compared.

RESULTS

There were no differences in demographic data, gastric emptying, orocecal transit or geometric center of transit in the colon between the two patient groups. The ARM and EMG studies suggested that the SPN group have a higher mean threshold volume of balloon distension required to initiate a rectoanal inhibitory reflex, and a higher incidence of anismus; however, this did not reach statistical significance.

CONCLUSIONS

These data suggest a trend that the SPN patients have a greater problem with obstructive defecation and abnormal rectal sensation than those with SPD. We were unable to confirm any defect in colonic transit in the SPD patients compared with the SPN group.

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.

Circulating gastrointestinal hormone abnormalities in patients with severe idiopathic constipation

OBJECTIVE

This study aimed to determine if there is an abnormality of circulating gastrointestinal hormones in patients with severe idiopathic constipation.

METHODS

Twelve patients, all female (median age 34 yr) and 12 healthy controls (eight female, median age 32 yr) were studied. A radioisotope-labeled solid/liquid meal was ingested, and the serum hormone response, as well as the relationship between serum hormones and rates of gastric emptying and small intestinal transit, were studied for 180 min postprandially.

RESULTS

Somatostatin levels were higher in patients with constipation (basal level, controls vs patients, 31 vs 57 pmol/L, p < 0.05, median values; peak level, 48 vs 60, p < 0.05). Patients showed a significantly lower somatostatin integrated incremental meal response (2182 vs 104, p < 0.05). No correlation was found between the somatostatin levels and rates of upper gastrointestinal transit in patients. Pancreatic glucagon was significantly decreased (p=0.04). Enteroglucagon levels were significantly lower (p > 0.05) in patients between 30 and 60 min after the meal. The peak found after the meal in normal subjects was absent. Basal levels of pancreatic glucagon correlated with small bowel transit by two different measures: head of meal (r=0.69, p=0.03) and cecal filling at the time of 50% gastric emptying (r=0.84, p=0.002). No significant differences between the two groups could be found for basal and peak levels at different times and integrated incremental response to the meal for insulin, gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK), gastrin, pancreatic polypeptide (PP), motilin, neurotensin, and peptide tyrosine tyrosine (PYY).

CONCLUSION

Patients with severe idiopathic constipation have specific abnormalities of circulating gut hormones that most likely play a role in gastrointestinal motility and that may be of pathophysiological significance.

Colonic neuroendocrine peptide levels in patients with chronic idiopathic slow transit constipation

The motility disorders in patients with slow-transit constipation have been attributed to a disturbance in the peptidergic innervation of the colonic enteric nervous system. The nature of this disturbance is, however, controversial. In the present study 7 patients with long-standing severe slow- transit constipation were included, and normal tissues from the colon of 6 patients, which had undergone colonectomy because of polyp, chronic diverticulitis, prolapsis and volvulus were used as controls. The concentrations of several neuroendocrine peptides were measured in tissue extracts by radioimmuno-assays. The level of pancreatic polypeptide was high in 2 patients and low in one patient. Peptide YY level was high in 3 patients and low in one patient, and that of neuropeptide Y was high in 4 patients. Somatostatin and vasoactive intestinal polypeptide levels were high in 3 patients and substance P concentration was low in 3 patients. Neurotensin level was high in one patient and low in another patient. Galanin concentration was low in 2 patients and high in one patient. Gastrin-releasing peptide level was high in one patient and that of enkephalin was high in 2 patients. All patients had altered concentrations of several neuroendocrine peptides except one, who had only a low level of galanin. It is concluded that patients with slow-transit constipation have disturbed neuroendocrine peptides in common, though the nature of this disturbance varies between patients and in most patients several neuroendocrine peptides were affected. This may explain the controversial results obtained in previous studies.

Upper gastrointestinal motor activity in patients with slow-transit constipation. Further evidence for an enteric neuropathy

Recent evidence indicates that patients complaining of severe chronic idiopathic constipation may have motor abnormalities not limited to the colon. We studied by manometric means gastric and small bowel motility in a homogeneous group of patients with chronic idiopathic constipation, ie, the slow transit type. Twenty-one patients were recruited for the study and compared to 33 healthy subjects. Manometric examination was carried out for about 5 hr fasting and 1 hr after a standard meal. Analysis of the manometric tracings revealed during fasting no abnormalities in number and configuration of migrating motor complex with respect to controls. However, in 70% of patients motor abnormalities were detected, represented by bursts of nonpropagated contractions and discrete clustered contractions. After feeding, the patient group displayed a significantly shorter antral motor response to the meal with respect to controls; moreover, intestinal bursts of nonpropagated contractions were found in 19% of patients, and 14% of them had an early return of the activity fronts. We conclude that patients with slow transit constipation frequently display motor abnormalities of the upper gut. These findings further strengthen the concept that this condition may represent a panenteric disorder.

Colectomy for severe slow-transit constipation in strictly selected patients

BACKGROUND

Colectomy for severe constipation has in up to 25% of patients given unsatisfactory results. Failure to cure constipation is in most patients due to rectal dysfunction. The aim of the present study was to evaluate the effect of colectomy in a group of patients who fulfil all the criteria which, with our present knowledge, should predict a favourable result.

METHODS

Twelve patients with long-standing severe constipation incurable by dietary regulation and medical treatment with demonstrable slow-transit constipation and normal rectal function entered the study.

RESULTS

Ten patients were relieved of their constipation. Two patients continued to be constipated after subtotal colectomy. One had a very highly compliant rectum (preoperatively) with a maximal tolerable volume of 700 ml but normal emptying at defecography and normal emptying of viscous fluid. The patient was subsequently treated with proctectomy and ileo-pouch-anal anastomosis with satisfactory result. One patient with opioid abuse due to abdominal pain was improved by the operation but was still constipated. The opioid abuse continued, however, after the operation owing to continuing abdominal pain. A further three patients complained of abdominal pain, and two developed diarrhoea, one of whom became incontinent.

CONCLUSION

Subtotal or segmental colectomy should be considered in a small number of patients with severe constipation provided strict criteria are fulfilled. Excessively high rectal volume tolerability may in spite of normal emptying capacity indicate the risk of development of rectal inertia postoperatively and may be a contraindication for surgery.

A long-term follow-up of patients undergoing colectomy for chronic idiopathic constipation

BACKGROUND

Chronic idiopathic constipation is a condition that mainly affects young women and is commonly associated with symptoms of abdominal pain and bloating. It has been proposed that patients with severe symptoms who are unresponsive to conservative measures can be managed by colonic resection. The aim of the present study was to assess the long-term outcome of such surgery on patients with a diagnosis of chronic idiopathic constipation.

METHODS

Ninety-six patients (92 females, 4 males) underwent either a total colectomy and ileorectal anastomosis (n = 86) or subtotal colectomy and caecorectal anastomosis (n = 10) between 1986 and 1994.

RESULTS

Postoperative mortality was 2.1%, 3.1% suffered from an anastomotic leak and 11.5% developed a pelvic abscess. Follow up was completed in 92.7% of patients at a mean of 5.0 +/- 2.3 years. Following surgery, symptomatic improvement was reported by 81.6% of patients. However, 51.2% still experienced difficulty with straining, 50.6% had some degree of anal incontinence, 55.2% continued to experience abdominal pains and 75.9% continued to be troubled by abdominal bloating. Reoperation was performed on 35.6% of patients (mainly for division of adhesions), and 9.2% of patients required an ileostomy.

CONCLUSIONS

Colectomy is associated with relief of constipation in a majority of patients with chronic idiopathic constipation. However, it is associated with a considerable morbidity and is less effective in resolving symptoms of abdominal pain and bloating.

Anorectal manometric abnormalities and colonic propulsive impairment in patients with severe chronic idiopathic constipation

Idiopathic chronic constipation is a frequent and disabling symptom, but its pathophysiological grounds are still poorly understood. In particular, there is little knowledge about the relationships between distal (anorectal area) and proximal (colonic area) motor abnormalities in this condition, especially concerning high-amplitude propagated colonic activity. For this purpose, we studied 25 patients complaining of severe idiopathic constipation and categorized them as normal- or slow-transit constipation according to colonic transit time. Twenty-five age-matched controls were also studied. Investigations included standard anorectal motility testing and prolonged (24-hr) colonic motility studies. Analysis of results showed that both groups of constipated patients displayed significantly different (P < 0.05) minimum relaxation volumes of the internal anal sphincter, defecatory sensation thresholds, and maximum rectal tolerable volumes with respect to controls. Patients with normal-transit constipation also showed lower internal anal sphincter pressure with respect to slow-transit constipation and controls (P < 0.001 and P < 0.02, respectively). The daily number of high-amplitude propagated contractions (mass movements) as well as their amplitude and duration, was significantly reduced in both subgroups of constipated patients (P < 0.02 vs controls). We conclude that (1) in normal-transit constipation, motor abnormalities are not limited to the anorectal area; (2) patients with slow-transit constipation probably have a severe neuropathic rectal defect; (3) prolonged colonic motility studies may highlight further the functional abnormalities in constipated subjects; and (4) an approach taking into account proximal and distal colon motor abnormalities might be useful to understand pathophysiological grounds of chronic constipation and lead to better therapeutic approaches.

Regional specificities in the distribution, chemical phenotypes, and coexistence patterns of neuropeptide containing nerve fibres in the human anal canal

Despite the pivotal clinical significance of the human anal canal, little is known about its total and specific innervation. This study assessed the comparative distribution and histotopology of nerve fibres immunoreactive for neural markers and a variety of regulatory active neuropeptides in the human anal canal by light microscopic immunohistochemistry. Depending on the epithelial zone and region of the anal canal, the neural elements were differentially immunoreactive for the pan-neural marker protein gene product 9.5, the catecholamine marker tyrosine hydroxylase, the neuroendocrine marker chromogranin A, and various neuropeptides. Protein gene product 9.5-immunoreactive nerve fibres were ubiquitously abundant in the anal canal. In the anal transitional zone, ectopic epithelial types were supplied by the same pattern of peptidergic nerves as the respective type of epithelium in normotopic location. In the dermis of the squamous zone and in the perianal epidermis, unusual distribution patterns of nerve fibres, referred to as areas of high nerve fibre density, were encountered. Double immunohistochemistry revealed region-specific coexistence patterns of neuropeptidergic nerve fibres, and novel peptide coexistence patterns were detected in anal nerve fibres. Subsets of nerve fibres formed close spatial relationships with chromogranin A-positive neuroendocrine cells, most frequently in the anal transitional zone. Chromogranin-A positive cells were shown to be present in the epithelium of perianal eccrine sweat glands. The differential distribution, peptide phenotypes and coexistence patterns of different nerve fibre populations in the human anal canal may reflect topospecific regulatory functions of neurally released neuropeptides in health and disease.