Intestinal pseudo-obstruction

Management of acute colonic pseudo-obstruction: opportunities to improve care?

BACKGROUND

Acute colonic pseudo-obstruction (ACPO) is a functional bowel obstruction characterised by colonic dilatation in the absence of mechanical obstruction on imaging. Complications include bowel ischaemia, perforation and death. The aim of this study was to explore outcomes for patients treated for ACPO and to assess adherence to current ACPO treatment guidelines.

METHODS

This is a retrospective service evaluation and included patients with a diagnosis of ACPO between 1 March 2018 and 31 March 2023. Process measures were identified following discussion with the clinical team from published guidance. Patients were identified using clinical coding and radiological text reports. Cases were eligible for inclusion if they had radiologically confirmed ACPO. Data were collected following review of patient notes into Microsoft Excel. Descriptive analysis was performed with no formal statistical assessment.

RESULTS

A total of 45 patients were identified, of whom 13 were admitted under general surgery. All patients received admission bloods (n=45). Nearly all patients had computed tomography imaging (43/45, 96%). Only 3/45 (6.7%) of the patients received optimal conservative management (intravenous infusion, nil by mouth, flatus tube, treatment of reversible causes). In all, 11/45 (24%) required further treatment, of whom 7 received this within 72 h. The leading (11/45) complication following diagnosis of ACPO was hospital-acquired pneumonia. Mortality was seen in 9/45.

CONCLUSIONS

ACPO is often managed remotely by general surgeons. This may impact on the quality of conservative management, and timeliness of endoscopic or pharmacological intervention. Further work is needed to optimise management.

An Atypical Initial Manifestation of Systemic Lupus Erythematosus: Lupus Enteritis Accompanied by Intestinal Pseudo-Obstruction and Bilateral Hydronephroureter

Systemic lupus erythematosus (SLE) is a systemic, autoimmune, multisystem disease. Lupus enteritis accompanied by intestinal pseudo-obstruction (IPO) is a serious and rare initial manifestation that can lead to high mortality and morbidity in case of delay in diagnosis and treatment. Here, we present a very complicated case of a 36-year-old female Pakistani patient with lupus enteritis accompanied by IPO and bilateral hydronephroureter. The patient had a three-month history of fever, weight loss, recurrent diarrhea, vomiting, alopecia, and photosensitivity. She had a malar and discoid rash, with signs and symptoms of IPO and neuropsychiatric lupus. Her labs revealed positive anti-nucleosome antibodies (8 U/mL), anti-Ro antibodies (100 U/mL), and anti-La antibodies (53 U/mL); equivocal anti-dsDNA antibodies (7 U/mL) and anti-Sm antibodies (7 U/mL); direct Coomb's positive hemolytic anemia; raised C-reactive protein and erythrocyte sedimentation rate levels; low complement (C3 and C4) levels; and pyuria. IPO was evident on abdominal X-ray and CT scan. Her Systemic Lupus Erythematosus Disease Activity Index was 24, indicating severe disease flare. She was treated with intravenous methylprednisolone, hydroxychloroquine, and intravenous 500 mg cyclophosphamide. Her lab parameters and clinical mini-mental score improved, from 0/30 to 18/30. She was discharged on oral prednisolone 0.5 mg/kg/day, hydroxychloroquine, trimethoprim-sulfamethoxazole (prophylaxis for Pneumocystis jirovecii pneumonia), and mineral and vitamin supplements. She was followed up on the 15th day of discharge for the next dose of cyclophosphamide, and her clinical and lab parameters were normal at that time with gradual improvement in cognition. Lupus enteritis with coexisting IPO and bilateral hydronephroureter poses a diagnostic and therapeutic challenge because of atypical and uncommon manifestations of lupus and overlapping features with intestinal tuberculosis and other inflammatory bowel conditions.

Intestinal pseudo-obstruction caused byGiardia lambliainfection

A woman in her 40s presented with malaise, nausea, reduced appetite, abdominal distention, loose stools and weight loss. Symptoms had started 6 months earlier and worsened in the last 2 weeks. CT enterography showed hypotonic dilated small bowel loops in absence of any mechanical obstruction. Endoscopic examinations including capsule endoscopy did not reveal any obstructing lesion, but a delayed small bowel transit time of the capsule. Duodenal histology revealed Marsh 3a villous atrophy. Secondary causes of intestinal pseudo-obstruction and villous atrophy were investigated.Giardia lambliatrophozoites were found in the stools and in the duodenal biopsies. The patient’s symptoms quickly resolved after metronidazole treatment with complete normalisation of duodenal histology.

Postinfectious T-lymphocytic enteral leiomyositis as a rare cause of chronic intestinal pseudoobstruction

T-lymphocytic enteral leiomyositis (T-lel) is a rare disorder causing chronic intestinal pseudo-obstruction (CIPO), with cases predominantly being reported in the field of veterinary and pediatric medicine. Here, we present a case of T-lel-associated CIPO in an adult female, who initially presented with a paralytic ileus 2 weeks after a common gastroenteritis. The histological diagnosis was established through full-thickness bowel biopsy, exhibiting a dense lymphocytic infiltrate in the lamina muscularis of the intestinal wall. This case shows that T-lel can be a cause of chronic intestinal pseudo-obstruction not only in children but also in adults. A subsequent induction of an immunosuppressive therapy with steroids, azathioprine, and ultimately TNF-alpha-inhibiting antibodies led to a slow recovery and stable disease.

Comparing Clinical, Imaging, and Physiological Correlates of Intestinal Pseudo-Obstruction: Systemic Sclerosis vs Amyloidosis and Paraneoplastic Syndrome

INTRODUCTION

Intestinal pseudo-obstruction is characterized by impaired transit and luminal dilation in the absence of mechanical obstruction. Our study aims to describe the clinical, radiographic, and physiological findings in pseudo-obstruction associated with systemic sclerosis (SSc), amyloidosis, and paraneoplastic syndrome.

METHODS

A retrospective cohort of patients evaluated at our institution between January 1, 2008, and August 1, 2018, was assembled. Clinical, imaging, and physiological characteristics were abstracted from electronic medical records.

RESULTS

We identified 100 cases of pseudo-obstruction (55 SSc, 27 amyloidosis, and 18 paraneoplastic). Female population predominance was seen in SSc (71%) vs male population in amyloidosis (74%). Most common symptom was abdominal bloating in all 3 groups. Vomiting was more common in SSc than amyloidosis (73% vs 46%, P = 0.02). Diarrhea was more common in amyloidosis and SSc compared with paraneoplastic (81% and 67% vs 28%, P < 0.01). Weight loss (>5%) was more common in SSc compared with amyloidosis and paraneoplastic (78% vs 31% and 17%, P < 0.0001). Only small bowel dilation was seen in 79%, 40%, and 44% and only large bowel dilation in 2%, 44%, and 44% of patients in SSc, amyloidosis, and paraneoplastic, respectively. Five of 8 SSc patients had myopathic and 3 of 5 paraneoplastic had neuropathic involvement on gastroduodenal manometry.

DISCUSSION

SSc-associated pseudo-obstruction demonstrates female population predominance and presents with vomiting, diarrhea, and weight loss. Amyloidosis-associated pseudo-obstruction shows male population predominance. Small bowel is more commonly involved than large bowel on both imaging and transit studies in SSc. Myopathic involvement was more common in SSc, contrary to neuropathic in paraneoplastic syndrome.

Ameliorating effects of sacral neuromodulation on gastric and small intestinal dysmotility mediated via a sacral afferent-vagal efferent pathway

BACKGROUND/AIMS

In a recent study of sacral nerve stimulation (SNS) for colonic inflammation, a possible spinal-vagal pathway was implicated. The aim of this study was to provide evidence for such a pathway by investigating the effects of SNS on dysmotility of the stomach and duodenum that are not directly innervated by the sacral efferents.

METHODS

Twenty-seven rats were chronically implanted with wire electrodes for SNS and gastrointestinal slow waves. SNS was performed in several acute sessions to investigate its effects on gastric/duodenal slow waves and emptying/transit impaired by glucagon and rectal distention (RD).

RESULTS

(a) SNS increased the percentage of normal gastric slow waves impaired by glucagon (from 53.9% to 77.0%, P < .0001) and RD (from 64% to 78%, P = .037). This improvement was abolished by atropine. (b) Similar effects were observed with SNS on duodenal slow waves, which was also blocked by atropine. (c) SNS normalized delayed gastric emptying induced by glucagon (control: 61.3%, glucagon: 44.3%, glucagon + SNS: 65.8%) and RD (control: 61.3%, RD: 46.7%, RD + SNS: 64.3%). It also normalized small intestinal transit delayed by RD (P = .001, RD + SNS vs RD; P = .9, RD + SNS vs control). (4) Both glucagon and RD induced an increase in the sympathovagal ratio (P = .007, glucagon vs baseline; P < .001, RD vs baseline) and SNS decreased the ratio (P = .006, glucagon + SNS vs glucagon; P = .04, RD + SNS vs RD).

CONCLUSIONS

Neuromodulation of the sacral nerve improves gastric and small intestinal pacemaking activity and transit impaired by glucagon and RD by normalizing the sympathovagal balance via a retrograde neural pathway from the sacral nerve to vagal efferents.

American Society for Gastrointestinal Endoscopy guideline on the role of endoscopy in the management of acute colonic pseudo-obstruction and colonic volvulus

Colonic volvulus and acute colonic pseudo-obstruction (ACPO) are 2 causes of benign large-bowel obstruction. Colonic volvulus occurs most commonly in the sigmoid colon as a result of bowel twisting along its mesenteric axis. In contrast, the exact pathophysiology of ACPO is poorly understood, with the prevailing hypothesis being altered regulation of colonic function by the autonomic nervous system resulting in colonic distention in the absence of mechanical blockage. Prompt diagnosis and intervention leads to improved outcomes for both diagnoses. Endoscopy may play a role in the evaluation and management of both entities. The purpose of this document from the American Society for Gastrointestinal Endoscopy's Standards of Practice Committee is to provide an update on the evaluation and endoscopic management of sigmoid volvulus and ACPO.

Acute colonic pseudo-obstruction: A systematic review of aetiology and mechanisms

AIM

To critically review the literature addressing the definition, epidemiology, aetiology and pathophysiology of acute colonic pseudo-obstruction (ACPO).

METHODS

A systematic search was performed to identify articles investigating the aetiology and pathophysiology of ACPO. A narrative synthesis of the evidence was undertaken.

RESULTS

No consistent approach to the definition or reporting of ACPO has been developed, which has led to overlapping investigation with other conditions. A vast array of risk factors has been identified, supporting a multifactorial aetiology. The pathophysiological mechanisms remain unclear, but are likely related to altered autonomic regulation of colonic motility, in the setting of other predisposing factors.

CONCLUSION

Future research should aim to establish a clear and consistent definition of ACPO, and elucidate the pathophysiological mechanisms leading to altered colonic function. An improved understanding of the aetiology of ACPO may facilitate the development of targeted strategies for its prevention and treatment.

Abdominal radiograph pearls and pitfalls for the emergency department radiologist: a pictorial review

Abdominal plain films are often the first imaging examination performed on a patient with abdominal pain in the emergency department. Radiograph findings can help guide clinical management and the need for advanced imaging. A pictorial review of a range of abdominal radiograph findings is presented, including bowel gas patterns, abdominal organ evaluation, pathologic gas, calcifications, implanted devices, and foreign bodies.

Cholinergic interactions between donepezil and prucalopride in human colon: potential to treat severe intestinal dysmotility

BACKGROUND AND PURPOSE

Cholinesterase inhibitors such as neostigmine are used for acute colonic pseudo-obstruction, but cardio-bronchial side-effects limit use. To minimize side-effects, lower doses could be combined with a 5-HT4 receptor agonist, which also facilitates intestinal cholinergic activity. However, safety concerns, especially in the elderly, require drugs with good selectivity of action. These include the AChE inhibitor donepezil (used for Alzheimer's disease, with reduced cardio-bronchial liability) and prucalopride, the first selective, clinically available 5-HT4 receptor agonist. This study examined their individual and potential synergistic activities in human colon.

EXPERIMENTAL APPROACH

Neuronally mediated muscle contractions and relaxations of human colon were evoked by electrical field stimulation (EFS) and defined phenotypically as cholinergic, nitrergic or tachykinergic using pharmacological tools; the effects of drugs were determined as changes in 'area under the curve'.

KEY RESULTS

Prucalopride increased cholinergically mediated contractions (EC50 855 nM; 33% maximum increase), consistent with its ability to stimulate intestinal motility; donepezil (477%) and neostigmine (2326%) had greater efficacy. Concentrations of donepezil (30-100 nM) found in venous plasma after therapeutic doses had minimal ability to enhance cholinergic activity. However, donepezil (30 nM) together with prucalopride (3, 10 μM) markedly increased EFS-evoked contractions compared with prucalopride alone (P = 0.04). For example, the increases observed with donepezil and prucalopride 10 μM together or alone were, respectively, 105 ± 35%, 4 ± 6% and 35 ± 21% (n = 3-7, each concentration).

CONCLUSIONS AND IMPLICATIONS

Potential synergy between prucalopride and donepezil activity calls for exploration of this combination as a safer, more effective treatment of colonic pseudo-obstruction.

Ghrelin and motilin receptor agonists: time to introduce bias into drug design

Ghrelin and motilin receptor agonists increase gastric motility and are attractive drug targets. However, 14 years after the receptors were described (18-24 years since ligands became available) the inactivity of the ghrelin agonist TZP-102 in patients with gastroparesis joins the list of unsuccessful motilin agonists. Fundamental questions must be asked. Pustovit et al., have now shown that the ghrelin agonist ulimorelin evokes prolonged increases in rat colorectal propulsion yet responses to other ghrelin agonists fade. Similarly, different motilin agonists induce short- or long-lasting effects in a cell-dependent manner. Together, these and other data create the hypothesis that the receptors can be induced to preferentially signal ('biased agonism') via particular pathways to evoke different responses with therapeutic advantages/disadvantages. Biased agonism has been demonstrated for ghrelin. Are motilin agonists which cause long-lasting facilitation of human stomach cholinergic function (compared with motilin) biased agonists (e.g., camicinal, under development for patients with gastric hypo-motility)? For ghrelin, additional complications exist because the therapeutic aims/mechanisms of action are uncertain, making it difficult to select the best (biased) agonist. Will ghrelin agonists be useful treatments of nausea and/or as suggested by Pustovit et al., chronic constipation? How does ghrelin increase gastric motility? As gastroparesis symptoms poorly correlate with delayed gastric emptying (yet gastro-prokinetic drugs can provide relief: e.g., low-dose erythromycin), would low doses of ghrelin and motilin agonists relieve symptoms simply by restoring neuromuscular rhythm? These questions on design and functions need addressing if ghrelin and motilin agonists are to reach patients as drugs.

The importance of interstitial cells of cajal in the gastrointestinal tract

Gastrointestinal (GI) motility function and its regulation is a complex process involving collaboration and communication of multiple cell types such as enteric neurons, interstitial cells of Cajal (ICC), and smooth muscle cells. Recent advances in GI research made a better understanding of ICC function and their role in the GI tract, and studies based on different types of techniques have shown that ICC, as an integral part of the GI neuromuscular apparatus, transduce inputs from enteric motor neurons, generate intrinsic electrical rhythmicity in phasic smooth muscles, and have a mechanical sensation ability. Absence or improper function of these cells has been linked to some GI tract disorders. This paper provides a general overview of ICC; their discovery, subtypes, function, locations in the GI tract, and some disorders associated with their loss or disease, and highlights some controversial issues with regard to the importance of ICC in the GI tract.

R, Santos R. Chronic intestinal pseudo-obstruction in a dog: case report

Intestinal pseudo-obstruction is a rare disorder that affects gastrointestinal propulsion. It may be secondary to several pathological conditions or it may develop without a known cause. A 1.2 year-old intact Pug bitch had a history of vomiting and constipation, which were followed by diarrhea and distended abdomen. Hypomotility and dilation of the small intestine, which was filled with gas, were observed during laparotomy. Histologically, full thickness biopsy specimens demonstrated a severe loss and degeneration of leiomyocytes in the inner and outer muscular layers of the intestinal wall, whereas there was a marked hypertrophy and hyperplasia of smooth muscle cells in the lamina propria, and extremely thickened muscularis mucosae arranged in bundles oriented in different directions with marked hypertrophy and hyperplasia of leiomyocytes. Distribution of leiomyocytes was further characterized by immunohistochemistry. These findings support the diagnosis of intestinal pseudo-obstruction in a Pug, associated with degeneration and loss of leiomyocytes in the muscular layer.

Cytokine-induced alterations of gastrointestinal motility in gastrointestinal disorders

Inflammation and immune activation in the gut are usually accompanied by alteration of gastrointestinal (GI) motility. In infection, changes in motor function have been linked to host defense by enhancing the expulsion of the infectious agents. In this review, we describe the evidence for inflammation and immune activation in GI infection, inflammatory bowel disease, ileus, achalasia, eosinophilic esophagitis, microscopic colitis, celiac disease, pseudo-obstruction and functional GI disorders. We also describe the possible mechanisms by which inflammation and immune activation in the gut affect GI motility. GI motility disorder is a broad spectrum disturbance of GI physiology. Although several systems including central nerves, enteric nerves, interstitial cells of Cajal and smooth muscles contribute to a coordinated regulation of GI motility, smooth muscle probably plays the most important role. Thus, we focus on the relationship between activation of cytokines induced by adaptive immune response and alteration of GI smooth muscle contractility. Accumulated evidence has shown that Th1 and Th2 cytokines cause hypocontractility and hypercontractility of inflamed intestinal smooth muscle. Th1 cytokines downregulate CPI-17 and L-type Ca²⁺ channels and upregulate regulators of G protein signaling 4, which contributes to hypocontractility of inflamed intestinal smooth muscle. Conversely, Th2 cytokines cause hypercontractilty via signal transducer and activator of transcription 6 or mitogen-activated protein kinase signaling pathways. Th1 and Th2 cytokines have opposing effects on intestinal smooth muscle contraction via 5-hydroxytryptamine signaling. Understanding the immunological basis of altered GI motor function could lead to new therapeutic strategies for GI functional and inflammatory disorders.

Colonic Pseudo-Obstruction with Distinct Transitional Zone in Adult Constipation Patients: Pathological Analysis and Results of Surgical Treatment

There are subsets of chronic constipation patients showing features of colonic pseudo-obstruction (CPO) with distinct transitional zone (TZ). We intended to analyze the clinicopathologic characteristics and surgical outcomes of these patients. Twenty-five consecutive patients who underwent surgery for constipation over the 9-year period were analyzed. TZ (+) group was defined as patients showing symptoms or signs of large bowel obstruction with dilated proximal and collapsed distal colon around the TZ at the time of operation, but without any evidence of mechanical causes of obstruction. Nineteen (76%) patients had features of CPO with TZ. All TZs were located in the left colon. Pathologically, segmental hypoganglionosis was identified at the TZ in all TZ (+) patients. On the other hand, pathologic diagnosis was intestinal neuronal dysplasia type B in the remaining six (24%) patients having a uniform colon diameter without demonstrable dilatations (TZ (-) group). Among TZ (+) patients, 17 (90%) underwent total colectomy with ileorectal anastomosis and two (10%) underwent enterostomy. Long-term follow-up (median 56 months) showed no recurrence of constipation in this group of patients. All six TZ (-) patients underwent total colectomy with ileorectal anastomosis and two (33%) of them had persistent symptoms of constipation on long-term follow-up (median 60 months). In a subset of adult constipation patients presenting with features of CPO with TZ, segmental hypoganglionosis was the final pathologic diagnosis. Constipation patients with features of CPO with distinct TZ in the left colon are expected to benefit from surgical intervention.

Emergency surgery in chronic intestinal pseudo-obstruction due to mitochondrial neurogastrointestinal encephalomyopathy: case reports

Chronic intestinal pseudo-obstruction (CIPO) is a syndrome characterized by recurrent clinical episodes of intestinal obstruction in the absence of any mechanical cause occluding the gut. There are multiple causes related to this rare syndrome. Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is one of the causes related to primary CIPO. MNGIE is caused by mutations in the gene encoding thymidine phosphorylase. These mutations lead to an accumulation of thymidine and deoxyuridine in blood and tissues of these patients. Toxic levels of these nucleosides induce mitochondrial DNA abnormalities leading to an abnormal intestinal motility.Herein, we described two rare cases of MNGIE syndrome associated with CIPO, which needed surgical treatment for gastrointestinal complications. In one patient, intra-abdominal hypertension and compartment syndrome generated as a result of the colonic distension forced to perform emergency surgery. In the other patient, a perforated duodenal diverticulum was the cause that forced to perform surgery. There is not a definitive treatment for MNGIE syndrome and survival does not exceed 40 years of age. Surgery only should be considered in some selected patients.

Polymorphisms of the RET gene in hirschsprung disease, anorectal malformation and intestinal pseudo-obstruction in Taiwan

BACKGROUND/PURPOSE

Mutations in the receptor tyrosine kinase RET gene are associated with Hirschsprung disease (HD), which is also known as congenital intestinal aganglionosis. We found an association with specific alleles in five single nucleotide polymorphism (SNP) sites of the RET gene in our HD patients.

METHODS

We compared the association of specific RET SNP alleles in patients with severe GI disorders such as anorectal malformation (ARM) or pediatric intestinal pseudo-obstruction (IPO) to that in HD patients. Sixty-four HD, 23 ARM and 35 IPO patients were included. Genomic DNA extracted from blood samples was analyzed by polymerase chain reaction and DNA sequencing analysis.

RESULTS

The allele distributions of all five RET SNPs in the HD patients deviated from those in the normal population (p < 0.05), whereas those of the ARM patients did not. The allele distributions of these RET SNPs in the IPO patients were all significantly different from those in the HD patients. Allele distributions of exon 2 and 13 in the IPO patients were also significantly different from those of the normal population. The frequencies of all the HD-predominant alleles were lower in the HD patients than the normal population, and were even lower in the IPO patients.

CONCLUSION

This study strengthens the association of specific RET SNP alleles with typical HD in Taiwan.

Visceral myopathy causing chronic intestinal pseudoobstruction and intestinal failure in a child with Sanjad-Sakati syndrome

Sanjad-Sakati syndrome is a rare autosomal recessive disorder mainly occurring in the Arab Peninsula. This condition is associated with metabolic and septic complications starting in the neonatal period. Chronic intestinal pseudoobstruction owing to visceral myopathy is a rare disabling condition. We report a rare concurrence of Sanjad-Sakati syndrome and chronic intestinal pseudoobstruction in a Saudi child complicated by intestinal failure, sepsis, and early mortality.

Clinical features and long-term survival in chronic intestinal pseudo-obstruction and enteric dysmotility

OBJECTIVE

Chronic intestinal pseudo-obstruction (CIP) is the most severe form of intestinal dysmotility. Enteric dysmotility (ED) has been proposed as a new diagnostic label for patients with disturbed intestinal motility and severe symptoms but no radiological signs of pseudo-obstruction. The purpose of this study was to compare the clinical features, small-bowel manometry findings and long-term survival in patients with CIP and ED.

MATERIAL AND METHODS

Data collected during a 16-year period from 1987 to 2002 were retrospectively analysed and followed-up through 2007 in a tertiary referral centre. The study comprised 55 patients (41 F, median age 42 years, range 23-76) with CIP and 70 patients (63 F, median age 39 years, range 18-71) with ED.

RESULTS

The median observation time was 9.9 years (range 5.2-20.1). Nineteen patients with CIP (35%) and 9 patients with ED (13%) died. Survival among patients with ED was significantly better (p<0.05). Patients with CIP (49%) needed parenteral nutrition more often than patients with ED (14%). Small-bowel manometry showed similar abnormalities in the two groups but absence of a fed motor response to meals was seen in 16/43 patients with CIP compared to none with ED (p<0.001), sustained periods of uncoordinated phasic activity were more common (p<0.05) in CIP patients (23/45) than in ED patients (19/70) and severe hypomotility was only seen in 7 patients with CIP.

CONCLUSIONS

CIP and ED differ with respect to severity of measurable physiological derangement, nutritional needs and long-term prognosis. Our findings indicate that CIP and ED are different entities that require different approaches to management.

Intestinal and anorectal motility and functional disorders

Motility and functional disorders of the small intestine, the colon and the anorectum can induce or contribute to symptoms such as diarrhoea, constipation and abdominal pain and may impair nutrient absorption in severe cases. Acute affections of intestinal functions e.g. during gastrointestinal infections usually need no functional diagnostics but resolve spontaneously or with adequate therapy of the underlying disease. By contrast, chronic disturbances of small intestinal, colonic and anorectal motility and/or sensitivity are subject to gastrointestinal function tests. The role of these tests for diagnosis and therapeutic handling of severe intestinal dysmotility/chronic intestinal pseudo-obstruction, severe constipation, diarrhoea, fecal incontinence and irritable bowel syndrome will be discussed in this review that mainly focuses on adults.

Interstitial cells of Cajal in the gut - A gastroenterologist’s point of view

Alterations of normal function of interstitial cells of Cajal (ICC) are reported in many intestinal disorders. Diagnosis of their involvement is rare (infrequent), but necessary to propose a specific treatment. This article reviews the place of ICC in the pathogenesis of achalasia, gastroesophageal reflux disease, infantile hypertrophic pyloric stenosis, chronic intestinal pseudo-obstruction and slow transit constipation. Moreover we discuss the role of the Cajal cells in the development of stromal tumors of the gastrointestinal tract.

Neurogenic chronic intestinal pseudo-obstruction: antineuronal antibody-mediated activation of autophagy via Fas

BACKGROUND & AIMS

Activation of autoimmune pathways has been implicated as a contributing mechanism to the pathophysiology in some patients with chronic intestinal pseudoobstruction (CIP). In this study we tested the hypothesis that sera from a subpopulation of patients with CIP contain autoantibodies that activate autophagy via a Fas-dependent pathway in cultured human neuroblastoma SH-Sy5Y cells.

METHODS

Twenty-five patients with established neurogenic CIP (20 women, 5 men; age range, 21-57 y) were investigated and circulating antineuronal antibodies to enteric neurons were found in 6 (24%) patients. The ability of antineuronal antibodies to induce autophagy was assessed using immunohistochemical, Western immunoblot, and molecular techniques. The presence of autophagosomes was monitored using a specific immunohistochemical marker, anti-microtubule-associated light chain immunoreactivity, and colocalization with mitochondrial- and Fas-activated death domain immunofluorescence using appropriate antibodies in cells exposed to sera from matched healthy controls and patients with neurogenic CIP.

RESULTS

Exposure of SH-Sy5Y cells to sera from patients with CIP containing antineuronal antibodies revealed increased binding of autoimmune immunoglobulin (IgG class) to the surface of SH-Sy5Y cells and increased formation of autophagosomes showing colocalization with mitochondria and Fas-activated death domain compared with control sera. Pretreatment of sera with either protein L agarose beads or a soluble Fas receptor (extracellular domain) chimera prevented the stimulation of autophagy.

CONCLUSIONS

We provide novel evidence that antineuronal antibodies may contribute to neuronal dysfunction observed in a subset of patients with neurogenic CIP via autoantibody-mediated activation of autophagy involving the Fas receptor complex.

Review article: molecular, pathological and therapeutic features of human enteric neuropathies

BACKGROUND

Considerable information has been gathered on the functional organization of enteric neuronal circuitries regulating gastrointestinal motility. However, little is known about the neuropathophysiological mechanisms underlying gastrointestinal motor disorders.

AIM

To analyse the most important pathological findings, clinical implications and therapeutic management of idiopathic enteric neuropathies.

METHODS

PubMed searches were used to retrieve the literature inherent to molecular determinants, pathophysiological bases and therapeutics of gastrointestinal dysmotility, such as achalasia, gastroparesis, chronic intestinal pseudo-obstruction, Hirschsprung's disease and slow transit constipation, to unravel advances on digestive disorders resulting from enteric neuropathies.

RESULTS

Current data on molecular and pathological features of enteric neuropathies indicate that degenerative and inflammatory abnormalities can compromise the morpho-functional integrity of the enteric nervous system. These alterations lead to a massive impairment in gut transit and result in severe abdominal symptoms with associated high morbidity, poor quality of life for patients and established mortality. Many pathophysiological aspects of these severe conditions remain obscure, and therefore treatment options are quite limited and often unsatisfactory.

CONCLUSIONS

This review of enteric nervous system abnormalities provides a framework to better understand the pathological processes underlying gut dysmotility, to translate this knowledge into clinical management and to foster the development of targeted therapeutic strategies.

Congenital visceral myopathy with a predominantly hypertrophic pattern treated by multivisceral transplantation

Chronic intestinal pseudoobstruction due to visceral myopathy may cause intestinal failure. The anatomical pathology of visceral myopathy is dominated by an atrophic muscularis propria. We present a case that is overwhelmingly dominated by a hypertrophic muscularis propria. The hypertrophic pattern was documented from ages 2 to 28 years. Most descriptions of visceral myopathy focus on the atrophic pattern of injury to the muscularis propria, typified by vacuolar degeneration of myocytes, loss of muscle fibers, and frequently with a honeycomb pattern of fibrosis. Hypertrophic changes can be observed in visceral myopathy, but the hypertrophy typically represents only a minor feature, typically limited to the internal layer of the muscularis propria. In our patient, the observed muscular hypertrophy differed from most descriptions because it (a) was the dominant pattern of injury and (b) involved both layers of muscularis propria rather than just the inner circular layer. The patient had intestinal failure and the complications induced cirrhosis, eventually treated by multivisceral transplantation to correct the intestinal failure and cirrhosis.

Impaired contractility of colonic muscle cells in a patient with chronic intestinal pseudo-obstruction

Chronic intestinal pseudo-obstruction represents a cause of persistent functional intestinal failure either "secondary" to specific conditions or "chronic intestinal idiopathic pseudo-obstruction" in origin. The diagnosis is mainly clinical, supported by radiological and/or endoscopic findings excluding any mechanical cause of intestinal obstruction. We reported a case of a 39-year-old woman with chronic intestinal idiopathic pseudo-obstruction, who underwent colectomy with ileorectal anastomosis; histological examination of the surgical specimen did not reveal myogenic or neurogenic defects or other pathological abnormalities indicative of an underlying neuromuscular impairment. Because of the apparent integrity of the gut neuromuscular layer, we tested whether a functional impairment affected colonic single smooth muscle cells. Muscle cells were isolated from the right colon and their contractile response to a receptor-dependent agonist evaluated in comparison to that obtained from controls. The cell contraction induced by acetylcholine in a dose response manner was markedly decreased in the patient affected by chronic intestinal idiopathic pseudo-obstruction compared with cells from controls (percentage of cell shortening with maximal dose of acetylcholine [10(-6)M]: 10.7+/-3% versus 34.2+/-4%, respectively). The present findings indicate a specific defect of colonic smooth muscle cells likely related to an ineffective response to acetylcholine.

A novel locus for syndromic chronic idiopathic intestinal pseudo-obstruction maps to chromosome 8q23-q24

Chronic idiopathic intestinal pseudo-obstruction (CIIP) is a rare and severe clinical syndrome characterized by symptoms and signs of intestinal occlusion, in the absence of any mechanical obstruction of the gut lumen. In the attempt to identify the genetic basis of CIIP, we analyzed a Turkish pedigree with a high degree of consanguinity in which three siblings presented with a syndromic form of CIIP. All affected family members were characterized by recurrent, self-limiting subocclusive episodes, long-segment Barrett esophagus, and a variety of minor cardiac valve or septal defects. In some patients full-thickness intestinal biopsy samples were obtained and tissues were processed for immunohistochemistry using antibodies to different markers of the intestinal neuromuscular tract. Full-thickness biopsies of the gut wall showed abnormalities of both the neural and muscular components suggesting an underlying intestinal neuro-myopathy. Blood samples were collected for DNA extraction from each available family member and DNAs were genotyped using 382 microsatellites spanning the entire genome with the aim to take advantage of the homozygosity mapping approach. Linkage analysis identified a new syndromic locus on chromosome 8q23-q24 (multipoint LOD score=5.01). Our data strongly support the presence of a new genetic locus associated with CIIP, long-segment Barrett esophagus, and cardiac involvement on chromosome 8.

Pseudo-obstruction intestinale chronique

Chronic intestinal pseudo-obstruction (CIPO) is a disease characterized by episodes resembling mechanical obstruction in the absence of organic, systemic, or metabolic disorders. Pseudo-obstruction is an uncommon condition and can result from primary (40%) or secondary (60%) causes. The most common symptoms are nausea, vomiting, abdominal distension, abdominal pain and constipation or diarrhea. These symptoms are usually present many years before CIPO diagnosis. They can lead to severe electrolyte disorders and malnutrition. Principles for management of patients with CIPO are: to establish a correct clinical diagnosis in excluding mechanical obstruction; to perform a symptomatic and physiologic assessment of the gastrointestinal tract involved; to look for extra-intestinal manifestations, especially for myopathy and neuropathy; to discuss in some cases a surgery for full-thickness intestinal biopsies, and/or a neuromuscular biopsy in case of mitochondrial cytopathy suspicion. The management is primarily focused on symptom control and nutritional support to prevent weight loss and malnutrition. Treatment of CIPO includes prokinetic agents which may help to reduce gastrointestinal symptoms Courses of antibiotics may be needed in patients with symptoms suggestive of bacterial overgrowth. When necessary, enteral nutrition is preferred. In carefully selected patients, feeding jejunostomy with or without decompression gastrostomy may be tried. Long term parenteral nutrition should be reserved for patients who can not tolerate enteral nutrition. Intestinal transplantation can be discussed in selected patients.

Management of patients with chronic abdominal pain in clinical practice

A practical approach to the management of chronic abdominal pain is needed, given the high prevalence and impact of this problem. This article describes an approach that has evolved based on clinical experience and review of the literature: identifying predominant bloaters and abdominal wall pain; exclusion of organic disease, including consideration of laparoscopy for diagnosis; consideration of chronic functional abdominal pain and the first and second line pharmacotherapies; and seeking specialist care in a pain clinic, psychiatry, or behavioural therapy.

Systematic review: acute colonic pseudo-obstruction

Acute colonic pseudo-obstruction is the clinical syndrome of acute large bowel dilatation without mechanical obstruction that is an important cause of morbidity and mortality. Acute colonic pseudo-obstruction occurs in hospitalized or institutionalized patients with serious underlying medical and surgical conditions. The pathogenesis of acute colonic pseudo-obstruction is not completely understood but likely results from an imbalance in the autonomic regulation of colonic motor function. Metabolic or pharmacological factors, as well as spinal or retroperitoneal trauma, may alter the autonomic regulation of colonic function, leading to excessive parasympathetic suppression or sympathetic stimulation. This imbalance results in colonic atony and dilatation. Early recognition and appropriate management are critical to minimizing morbidity and mortality. The mortality rate is estimated at 40% when ischaemia or perforation occurs. The best-studied treatment of acute colonic pseudo-obstruction is intravenous neostigmine, which leads to prompt colon decompression in the majority of patients after a single infusion. In patients failing or having contraindications to neostigmine, colonoscopic decompression is the active intervention of choice. Surgery is reserved for those with peritonitis or perforation.

Spinal anesthesia and Ogilvie's syndrome

Ogilvie's syndrome is an uncommon disorder of acute colonic pseudoobstruction that is often associated with concomitant medical disease or psychiatric medication. Therapeutic interventions include cholinesterase inhibitors, colonic decompression, and, in severe cases, surgery. We report a case of functional obstruction that was resolved after spinal anesthesia. The effect of spinal anesthesia on the autonomic control of colonic motility is discussed, and the literature on neuraxial blockade and Ogilvie's syndrome is reviewed.

Natural history of chronic idiopathic intestinal pseudo-obstruction in adults: a single center study

BACKGROUND & AIMS

Chronic idiopathic intestinal pseudo-obstruction (CIIP) is a rare disease characterized by episodes resembling mechanical obstruction in the absence of organic, systemic, or metabolic disorders. Intestinal motor abnormalities have long been identified in CIIP patients. Little is known of the natural history of the disease in adults. This study evaluated the clinical course of CIIP over time.

METHODS

Fifty-nine consecutive CIIP patients without underlying collagen, vascular diseases, or mitochondrial cytopathies were evaluated between 1985 and 2001. Family history, onset of digestive symptoms, previous surgeries, episodes suggestive of subacute intestinal obstruction, digestive symptoms, body mass index, and feeding habits were recorded. Small bowel manometry was performed by a perfusion technique, and abnormal motor patterns were visually identified. Full-thickness biopsies were available in 11 cases and were processed for immunohistochemical analysis of myogenic and neurogenic components of the gut wall.

RESULTS

Patients were prospectively followed up for a median of 4.6 years (range, 1-13 years). Diagnosis was often made several years after symptom onset (median, 8 years). Thus, the majority of patients (88%) underwent useless and potentially dangerous surgeries (mean, 2.96 per patient). Manometry invariably showed abnormal motor patterns. Pathologic findings included neuropathies in all investigated cases and abnormalities of interstitial cells of Cajal in 5 of 11 cases. Long-term outcome was generally poor despite surgical and medical therapies; 4 patients died of disease-related complications, 4 underwent small bowel transplantation, almost one third required long-term home parenteral nutrition, and two thirds had some sort of nutritional limitations.

CONCLUSIONS

CIIP is a severe, often unrecognized disease characterized by disabling and potentially life-threatening complications over time.

Chronic Intestinal Pseudo-Obstruction

Chronic intestinal pseudo-obstruction (CIP) is a gastrointestinal motility disorder characterized by chronic symptoms and signs of bowel obstruction in the absence of a fixed, lumen-occluding lesion. Radiographic findings consist of dilated bowel with air-fluid levels. Pseudo-obstruction is an uncommon condition and can result from primary or secondary causes. The management is primarily focused on symptom control and nutritional support to prevent weight loss and malnutrition. The principles of management of patients with CIP involve 1) establishing a correct clinical diagnosis and excluding mechanical obstruction; 2) differentiating between idiopathic and secondary forms; 3) performing a symptomatic and physiologic assessment of the parts of the gastrointestinal (GI) tract involved by manometric and whole gut transit scintigraphic studies; 4) careful assessment of nutritional status of the patient; and 5) developing a therapeutic plan addressing the patient's symptoms and nutritional status. Treatment of CIP includes frequent small meals with a low-fat, low-fiber diet, liquid nutritional supplements may be needed; prokinetic agents such as metoclopramide may help to reduce upper GI symptoms. Trials of drugs such as erythromycin, domperidone, cisapride, and tegaserod may be considered if there is no response. Subcutaneous octreotide may be helpful to improve small bowel dysmotility especially in patients with scleroderma. In patients with symptoms suggestive of bacterial overgrowth, courses of antibiotics such as metronidazole, ciprofloxacin, and doxycycline may be needed. Nutritional assessment and support is an important aspect of management. Enteral nutrition is usually preferred. In carefully selected patients, feeding jejunostomy with or without decompression gastrostomy may be tried. Long term parenteral nutrition should be reserved for patients who can not tolerate enteral nutrition. Complications associated with total parenteral nutrition include infections, sepsis, and cholestatic hepatic dysfunction.

Pseudo-pseudo-obstruction

Chronic intestinal pseudo-obstruction is a clinical syndrome characterised by symptoms and signs of intestinal obstruction in the absence of a mechanical lesion of the intestinal lumen. The diagnosis is often difficult and relies on clinical, radiological and manometric grounds. We present here a case in which such a diagnosis was suspected, but a thorough in-depth evaluation revealed that the symptoms were due to a treatable cause--abdominopelvic adhesions.

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.

Intestinal transplantation for chronic intestinal pseudo-obstruction in adult patients

Intestinal transplantation (ITx) has become a life-saving procedure for patients with irreversible intestinal failure who can no longer be maintained on parenteral nutrition (PN). This report presents the results of our experience on ITx in patients suffering from chronic intestinal pseudo-obstruction (CIPO). Between December 30, 2000 and May 30, 2003 six adult patients affected by CIPO underwent primary ITx at our Center. Pre-transplant evaluation, indication for ITx and surgical technique are reported. On December 30 2003, the mean follow-up was 25.0 months. No peri-operative deaths occurred in the study population and five out of six patients are alive, with 1-year patient and graft survival of 83.3% and 66.6%. Although our series is limited by the number of patients, our experience suggests that ITx transplantation should be considered in adult patients suffering from CIPO and PN life-threatening complication.

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.

Treating irritable bowel syndrome: overview, perspective and future therapies

This article summarizes the ongoing challenges in irritable bowel syndrome and the exciting opportunities for development of novel therapies for this common, enigmatic condition. The challenges include insufficient understanding of mechanisms, lack of specificity of symptoms, differentiation from other conditions, and lack of availability of noninvasive tests to identify dysfunctions. However, significant opportunities are reflected by the advances in clinical trial design and, particularly, clinically relevant end points for such trials, and the increasing understanding of basic neuroenteric science. The latter has delivered two new medications to the practice (alosetron and tegaserod), and other candidate therapies (other serotonergic, tachykininergic, opioid, cannabinoid modulators) are being carefully appraised as potential drugs for the future.