Efficacy and safety of rifaximin in patients with chronic intestinal pseudo-obstruction: a randomized, double-blind, placebo-controlled, phase II-a exploratory trial.

Chronic intestinal pseudo-obstruction (CIPO) is a rare intractable disease with limited treatment options. Small intestinal bacterial overgrowth (SIBO) often co-occurs with several diseases, including CIPO. While rifaximin (RFX) is effective in treating SIBO, its efficacy for CIPO remains unclear. Here, we aimed to investigate the efficacy and safety of RFX in adult patients with CIPO. Twelve patients were randomly assigned to receive RFX (400 mg three times daily, n=8) or a placebo (PBO, n=4) for 4 weeks. The global symptom score for abdominal bloating (GSS-bloating) and an original whole gastrointestinal symptoms score (O-WGSS) were collected, and a glucose hydrogen breath test (GHBT) and abdominal computed tomography (CT) were performed. No significant differences were observed in the primary endpoint. GSS-bloating improved by 75% and 25% in the PBO and RFX groups, respectively, and O-WGSS improved by 25% in both groups. No significant differences were observed in secondary and other endpoints, including the SIBO eradication rate in the GHBT and small intestinal volume on CT. In a post hoc analysis of SIBO-positive patients with CIPO (4/4 and 4/8 in the PBO and RFX groups), SIBO was eradicated in 25% and 75% of the patients (PBO and RFX groups, respectively) at the end of treatment, indicating a high eradication rate in the RFX group. Furthermore, the small intestinal gas volume decreased in the RFX group, and no severe adverse events occurred. Although no significant improvements were observed in subjective indicators, RFX may be beneficial in alleviating SIBO and reducing the small intestinal gas volume in SIBO-positive patients with CIPO.

Bowel function and inflammation: Is motility the other side of the coin?

Digestion and intestinal absorption allow the body to sustain itself and are the emblematic functions of the bowel. On the flip side, functions also arise from its role as an interface with the environment. Indeed, the gut houses microorganisms, collectively known as the gut microbiota, which interact with the host, and is the site of complex immune activities. Its role in human pathology is complex and scientific evidence is progressively elucidating the functions of the gut, especially regarding the pathogenesis of chronic intestinal diseases and inflammatory conditions affecting various organs and systems. This editorial aims to highlight and relate the factors involved in the pathogenesis of intestinal and systemic inflammation.

Chronic intestinal pseudo-obstruction: associations with gut microbiota and genes expression of intestinal serotonergic pathway.

BACKGROUND: Pediatric chronic intestinal pseudo-obstruction (PIPO) is a rare disease characterized by symptoms and radiological signs suggestive of intestinal obstruction, in the absence of lumen-occluding lesions. It results from an extremely severe impairment of propulsive motility. The intestinal endocrine system (IES) jointly with the enteric nervous system (ENS) regulates secreto-motor functions via different hormones and bioactive messengers/neurotransmitters. The neurotransmitter 5-hydroxytryptamine (5-HT) (or serotonin) is linked to intestinal peristalsis and secretory reflexes. Gut microbiota and its interplay with ENS affect 5-HT synthesis, release, and the subsequent serotonin receptor activation. To date, the interplay between 5-HT and gut microbiota in PIPO remains largely unclear. This study aimed to assess correlations between mucosa associated microbiota (MAM), intestinal serotonin-related genes expression in PIPO. To this purpose, biopsies of the colon, ileum and duodenum have been collected from 7 PIPO patients, and 7 age-/sex-matched healthy controls. After DNA extraction, the MAM was assessed by next generation sequencing (NGS) of the V3-V4 region of the bacterial RNA 16 S, on an Illumina Miseq platform. The expression of genes implicated in serotoninergic pathway (TPH1, SLC6A4, 5-HTR3 and 5-HTR4) was established by qPCR, and correlations with MAM and clinical parameters of PIPO have been evaluated. RESULTS: Our results revealed that PIPO patients exhibit a MAM with a different composition and with dysbiosis, i.e. with a lower biodiversity and fewer less connected species with a greater number of non-synergistic relationships, compared to controls. qPCR results revealed modifications in the expression of serotonin-related intestinal genes in PIPO patients, when compared to controls. Correlation analysis do not reveal any kind of connection. CONCLUSIONS: For the first time, we report in PIPO patients a specific MAM associated to underlying pathology and an altered intestinal serotonin pathway. A possible dysfunction of the serotonin pathway, possibly related to or triggered by an altered microbiota, may contribute to dysmotility in PIPO patients. The results of our pilot study provide the basis for new biomarkers and innovative therapies targeting the microbiota or serotonin pathways in PIPO patients.

[Severe small bowel involvement and chronic intestinal pseudo-obstruction in systemic sclerosis (scleroderma): Pathophysiological, diagnostic and therapeutic basis, including parenteral nutrition]. / Atteinte sévère de l'intestin grêle et pseudo-obstruction intestinale chronique au cours de la sclérodermie systémique : bases physiopathologiques, diagnostiques et thérapeutiques, dont la nutrition parentérale.

Gastrointestinal involvement in systemic sclerosis can be severe, reaching the critical point of chronic intestinal pseudo-obstruction, secondary to major disorders of small bowel motility. It is associated with some clinical and biological characteristics, in particular the positivity of anti-fibrillarin/U3RNP antibodies. Chronic intestinal pseudo-obstruction (CIPO) is complicated by a small intestinal bacterial overgrowth that requires cyclic antibiotic therapy. CIPO leads to a reduction of the food intake, due to painful symptoms, nausea and vomiting caused by meals, and ultimately to severe malnutrition. Meal splitting is often transiently effective and patients require exogenous nutritional support, mostly parenteral. Systemic sclerosis is not an obstacle to initiation and long-term continuation of parenteral nutrition and central venous catheter implantation is not associated with an increased risk of cutaneous or infectious complications. However, continuation of long-term parenteral nutrition requires monitoring in an expert nutrition center in order to adapt nutritional volumes and intakes and to limit potentially fatal cardiac and hepatobiliary complications. In addition to nutrition, prokinetic treatments, whose side effects must be known, can be associated. Invasive procedures, whose risk-benefit ratio must be carefully assessed, can also be used to treat symptoms exclusively.

Chronic intestinal pseudo-obstruction due to adult-onset acquired isolated hypoganglionosis with muscular atrophy in the small intestine: a case report and review of literature.

BACKGROUND: Chronic intestinal pseudo-obstruction (CIPO) is a rare intestinal disorder characterized by impaired propulsion of the digestive tract and associated with symptoms of intestinal obstruction, despite the absence of obstructive lesions. CIPO includes several diseases. However, definitive diagnosis of its etiology is difficult only with symptoms or imaging findings. CASE PRESENTATION: A 56-year-old man was referred to our hospital due to a 3-year history of continuous abdominal distention. Imaging, including computed tomography of the abdomen, and endoscopy revealed marked dilatation of the entire small intestine without any obstruction point. Therefore, he was diagnosed with CIPO. Since medical therapy didn't improve his symptoms, enterostomy and percutaneous endoscopic gastro-jejunostomy were performed. These procedures improved abdominal symptoms. However, he required home central venous nutrition due to dehydration. The pathological findings of full-thickness biopsies of the small intestine taken during surgery revealed decreased number and degeneration of ganglion cells in the normal plexus. These findings led to a final diagnosis of CIPO due to acquired isolated hypoganglionosis (AIHG). CONCLUSIONS: Here, we report the case of a patient with CIPO secondary to adult-onset AIHG of the small intestine. Since AIHG cannot be solely diagnosed using clinical findings, biopsy is important for its diagnosis.

Dilated gut conditions: diagnosis and management.

Dilatation of the gut occurs in response to either mechanical obstruction or aperistalsis. The hallmark features are symptoms of bowel obstruction with vomiting, constipation, abdominal pain and distension. This review will primarily deal with the non-mechanical causes of gut dilatation, both intestinal and colonic, and differentiate between acute and chronic presentations.

A case of comorbidity of schizophrenic catatonia and chronic intestinal pseudo-obstruction Successfully managed with lorazepam.

It is challenging to manage schizophrenic catatonia and comorbid chronic intestinal pseudo-obstruction (CIPO). The pathology of catatonia is unclear. There are few reports or research on this issue. In this case, we present a middle-aged woman diagnosed with schizophrenia with catatonic features and comorbid CIPO. In the treatment process, modified electroconvulsive therapy (mECT) improved her stupor and CIPO partially. Lorazepam alleviated her stupor and CIPO completely. It is the first report describing complete remission with lorazepam in patient suffering from comorbid schizophrenic catatonia and CIPO, which may benefit the exploration of pathophysiology and treatment of comorbidity of schizophrenia with catatonia and CIPO.

Multi-disciplinary Insights from the First European Forum on Visceral Myopathy 2022 Meeting.

Visceral myopathy is a rare, life-threatening disease linked to identified genetic mutations in 60% of cases. Mostly due to the dearth of knowledge regarding its pathogenesis, effective treatments are lacking. The disease is most commonly diagnosed in children with recurrent or persistent disabling episodes of functional intestinal obstruction, which can be life threatening, often requiring long-term parenteral or specialized enteral nutritional support. Although these interventions are undisputedly life-saving as they allow affected individuals to avoid malnutrition and related complications, they also seriously compromise their quality of life and can carry the risk of sepsis and thrombosis. Animal models for visceral myopathy, which could be crucial for advancing the scientific knowledge of this condition, are scarce. Clearly, a collaborative network is needed to develop research plans to clarify genotype-phenotype correlations and unravel molecular mechanisms to provide targeted therapeutic strategies. This paper represents a summary report of the first 'European Forum on Visceral Myopathy'. This forum was attended by an international interdisciplinary working group that met to better understand visceral myopathy and foster interaction among scientists actively involved in the field and clinicians who specialize in care of people with visceral myopathy.

[Gastrointestinal tract involvement in systemic sclerosis]. / Atteinte digestive de la sclérodermie systémique.

Gastrointestinal tract involvement in systemic sclerosis concerns more than 90% of patients but is of heterogeneous clinical expression. It can involve the entire intestinal tract and be responsible for multifactorial malnutrition, which is frequent in this disease. It is a major source of deterioration in the quality of life and can even be life-threatening. Management is complex and multidisciplinary, ranging from simple hygienic and dietary measures, to specialized endoscopic or surgical interventional procedures, also including medical treatments, particularly proton pump inhibitors and prokinetics, with potential side effects. Ongoing research for new diagnostic and therapeutic tools promises to improve the management and prognosis of these patients.

Pyridostigmine in chronic intestinal pseudo-obstruction - a systematic review.

BACKGROUND: Chronic intestinal pseudo-obstruction (CIPO) may be a primary or secondary phenomenon and is often multifactorial. Treatment is largely directed at improving colonic motility. The use of cholinesterase inhibitors such as pyridostigmine has been hypothesized to increase acetylcholine in the bowel, improving symptoms and transit times. METHODS: A systematic review of the use of pyridostigmine in CIPO was conducted using scientific and commercial search engines identifying scientific studies enrolling adult human subjects, published from 2000 to 2022 in the English language. RESULTS: Four studies were identified including two randomized controlled trials (RCT) and two observational studies. The studies had heterogenous inclusion criteria, dosing regimens and reported outcomes. Two studies were identified as being at high risk of bias. All studies reported improved patient outcomes with use of pyridostigmine, and low rates (4.3%) of mild cholinergic side effects. No major side effects were reported. CONCLUSION: The use of pyridostigmine in management of CIPO is biologically plausible due to its ability to increase colonic motility, and early studies on its role are uniformly suggestive of benefit with low side-effect profile. Four clinical studies have been conducted to date, with small sample sizes, heterogeneity and high risk of bias. Further high-quality studies are required to enable assessment of pyridostigmine's utility as an effective management strategy in CIPO.

Utility of orcein stain and comparison with Masson trichrome stain in chronic intestinal pseudo-obstruction.

Chronic intestinal pseudo-obstruction (CIPO) is caused by a plethora of primary and secondary causes, dominantly involving the neuromuscular tissue, interstitial cells of Cajal, or the connective tissue framework. The lack of the connective tissue framework, known as desmosis, is evaluated by Masson's trichrome (MT) or picrosirius red stains, both of which are recommended in the London classification. We evaluated the orcein stain in detecting desmosis in comparison to the MT stain. We performed both orcein and MT stains in six previously published cases of complete or partial desmosis along with six age-matched controls. Our results showed comparable results of the orcein stain as compared to the MT stain. Additional advantages of lower cost and a clearer background in orcein stain were noteworthy, whereas MT stain can be used for the detection of additional pathology. We believe that orcein stain can be used as a cheap alternative in resource-limited settings.

Clinical and Pathological Features of Severe Gut Dysmotility.

Severe gut motility disorders are characterized by ineffective propulsion of intestinal contents. As a result, patients often develop extremely uncomfortable symptoms, ranging from nausea and vomiting along with alterations of bowel habits, up to radiologically confirmed subobstructive episodes. Chronic intestinal pseudo-obstruction (CIPO) is a typical clinical phenotype of severe gut dysmotility due to morphological and functional alterations of the intrinsic (enteric) innervation and extrinsic nerve supply (hence neuropathy), interstitial cells of Cajal (ICCs) (mesenchymopathy), and smooth muscle cells (myopathy). In this chapter, we highlight some molecular mechanisms of CIPO and review the clinical phenotypes and the genetics of the different types of CIPO. Specifically, we will detail the role of some of the most representative genetic mutations involving RAD21, LIG3, and ACTG2 to provide a better understanding of CIPO and related underlying neuropathic or myopathic histopathological abnormalities. This knowledge may unveil targeted strategies to better manage patients with such severe disease.

Enteric Neuromyopathies: Highlights on Genetic Mechanisms Underlying Chronic Intestinal Pseudo-Obstruction.

Severe gut motility disorders are characterized by the ineffective propulsion of intestinal contents. As a result, the patients develop disabling/distressful symptoms, such as nausea and vomiting along with altered bowel habits up to radiologically demonstrable intestinal sub-obstructive episodes. Chronic intestinal pseudo-obstruction (CIPO) is a typical clinical phenotype of severe gut dysmotility. This syndrome occurs due to changes altering the morpho-functional integrity of the intrinsic (enteric) innervation and extrinsic nerve supply (hence neuropathy), the interstitial cells of Cajal (ICC) (mesenchymopathy), and smooth muscle cells (myopathy). In the last years, several genes have been identified in different subsets of CIPO patients. The focus of this review is to cover the most recent update on enteric dysmotility related to CIPO, highlighting (a) forms with predominant underlying neuropathy, (b) forms with predominant myopathy, and (c) mitochondrial disorders with a clear gut dysfunction as part of their clinical phenotype. We will provide a thorough description of the genes that have been proven through recent evidence to cause neuro-(ICC)-myopathies leading to abnormal gut contractility patterns in CIPO. The discovery of susceptibility genes for this severe condition may pave the way for developing target therapies for enteric neuro-(ICC)-myopathies underlying CIPO and other forms of gut dysmotility.

Smooth muscle motility disorder phenotypes: A systematic review of cases associated with seven pathogenic genes (ACTG2, MYH11, FLNA, MYLK, RAD21, MYL9 and LMOD1).

Smooth muscle disorders affecting both the intestine and the bladder have been known for a decade. However, the recent discovery of genes associated with these dysfunctions has led to the description of several clinical phenotypes. We performed a systematic review of all published cases involving seven genes with pathogenic variants, ACTG2, MYH11, FLNA, MYLK, RAD21, MYL9 and LMOD1, and included 28 articles describing 112 patients and 5 pregnancies terminated before birth. The most commonly described mutations involved ACTG2 (75/112, 67% of patients), MYH11 (14%) and FLNA (13%). Twenty-seven patients (28%) died at a median age of 14.5 months. Among the 76 patients for whom this information was available, 10 (13%) had isolated chronic intestinal pseudo-obstruction (CIPO), 17 (22%) had isolated megacystis, and 48 (63%) had combined CIPO and megacystis. The respective proportions of these phenotypes were 9%, 20% and 71% among the 56 patients with ACTG2 mutations, 20%, 20% and 60% among the 10 patients with MYH11 mutations and 50%, 50% and 0% among the 7 patients with FLNA mutations.

TFAP2B Haploinsufficiency Impacts Gastrointestinal Function and Leads to Pediatric Intestinal Pseudo-obstruction.

Background: Pediatric Intestinal Pseudo-obstruction (PIPO) is a congenital enteric disorder characterized by severe gastrointestinal (GI) dysmotility, without mechanical obstruction. Although several genes have been described to cause this disease, most patients do not receive a genetic diagnosis. Here, we aim to identify the genetic cause of PIPO in a patient diagnosed with severe intestinal dysmotility shortly after birth. Methods: Whole exome sequencing (WES) was performed in the patient and unaffected parents, in a diagnostic setting. After identification of the potential disease-causing variant, its functional consequences were determined in vitro and in vivo. For this, expression constructs with and without the causing variant, were overexpressed in HEK293 cells. To investigate the role of the candidate gene in GI development and function, a zebrafish model was generated where its expression was disrupted using CRISPR/Cas9 editing. Results: WES analysis identified a de novo heterozygous deletion in TFAP2B (NM_003221.4:c.602-5_606delTCTAGTTCCA), classified as a variant of unknown significance. In vitro studies showed that this deletion affects RNA splicing and results in loss of exon 4, leading to the appearance of a premature stop codon and absence of TFAP2B protein. Disruption of tfap2b in zebrafish led to decreased enteric neuronal numbers and delayed transit time. However, no defects in neuronal differentiation were detected. tfap2b crispants also showed decreased levels of ednrbb mRNA, a downstream target of tfap2b. Conclusion: We showed that TFAP2B haploinsufficiency leads to reduced neuronal numbers and GI dysmotility, suggesting for the first time, that this gene is involved in PIPO pathogenesis.

Small intestine motility disorders: Chronic intestinal pseudo-obstruction.

Chronic intestinal pseudo-obstruction (CIPO) is a syndrome associating chronic or recurrent obstructive symptoms with intestinal dilation on imaging but without organic obstruction in the digestive tract. It is a rare disease with varying severity whose diagnosis is very complex. The diagnosis is based on clinical and paraclinical arguments in the context of repetitive occlusive syndromes when no mechanical obstruction of the digestive lumen is observed. Abdomino-pelvic computerized tomography (CT) must be performed to rule out a mechanical obstruction. An additional reference examination is trans-duodenal manometry of the small intestine, which is almost never normal in CIPO, but the test is rarely systematically performed. CIPO can be primary (acquired or congenital) or secondary to a systemic pathology (neurological, metabolic, etc.) resulting in neuromuscular damage to the intestinal tract. There are familial forms associated with genetic mutations. The majority of CIPO cases are idiopathic. Symptoms of the CIPO syndrome should be investigated with a complete assessment, guided by questioning and clinical examination that should also focus on urinary, neurological and cardiac involvement. Pathological tissue analysis is interesting for the etiological classification but is difficult to obtain. CIPO must be distinguished from non-CIPO intestinal dysmotility. Management must be carried out in an expert center with multidisciplinary care involving gastroenterologists, nutritionists, psychologists, radiologists, pathologists and digestive surgeons. It is essentially based on symptomatic management (especially with pro-kinetic agents and analgesics), nutritional support, as well as psychological support in view of its impact on quality of life. Surgical management is sometimes necessary.

Chronic Intestinal Pseudo-obstruction with Mitochondrial Diseases.

Chronic intestinal pseudo-obstruction (CIPO) is a rare disorder of intestinal dysmotility characterized by chronic symptoms, including vomiting and abdominal pain, associated with bowel obstruction without any mechanical obstructive causes. We herein report a case of mitochondrial diseases with recurrent duodenal obstruction that was initially diagnosed as superior mesenteric artery syndrome (SMAS) for a few years but was later diagnosed as CIPO. Since CIPO is known to be associated with mitochondrial diseases, it should be considered in the differential diagnosis of patients with mitochondrial diseases presenting with recurrent intestinal obstruction.