Novel therapies for constipation

Idiopathic Slow Transit Constipation: Pathophysiology, Diagnosis, and Management

Slow transit constipation (STC) has an estimated prevalence of 2-4% of the general population, and although it is the least prevalent of the chronic constipation phenotypes, it more commonly causes refractory symptoms and is associated with significant psychosocial stress, poor quality of life, and high healthcare costs. This review provides an overview of the pathophysiology, diagnosis, and management options in STC. STC occurs due to colonic dysmotility and is thought to be a neuromuscular disorder of the colon. Several pathophysiologic features have been observed in STC, including reduced contractions on manometry, delayed emptying on transit studies, reduced numbers of interstitial cells of Cajal on histology, and reduced amounts of excitatory neurotransmitters within myenteric plexuses. The underlying aetiology is uncertain, but autoimmune and hormonal mechanisms have been hypothesised. Diagnosing STC may be challenging, and there is substantial overlap with the other clinical constipation phenotypes. Prior to making a diagnosis of STC, other primary constipation phenotypes and secondary causes of constipation need to be ruled out. An assessment of colonic transit time is required for the diagnosis and can be performed by a number of different methods. There are several different management options for constipation, including lifestyle, dietary, pharmacologic, interventional, and surgical. The effectiveness of the available therapies in STC differs from that of the other constipation phenotypes, and prokinetics often make up the mainstay for those who fail standard laxatives. There are few available management options for patients with medically refractory STC, but patients may respond well to surgical intervention. STC is a common condition associated with a significant burden of disease. It can present a clinical challenge, but a structured approach to the diagnosis and management can be of great value to the clinician. There are many therapeutic options available, with some having more benefits than others.

Neurogenic Bowel and Management after Spinal Cord Injury: A Narrative Review

People with spinal cord injury (SCI) suffer from the sequela of neurogenic bowel and its disabling complications primarily constipation, fecal incontinence, and gastrointestinal (GI) symptoms. Neurogenic bowel is a functional bowel disorder with a spectrum of defecatory disorders as well as colonic and gastrointestinal motility dysfunction. This manuscript will review the anatomy and physiology of gastrointestinal innervation, as well as the pathophysiology associated with SCI. It will provide essential information on the recent guidelines for neurogenic bowel assessment and medical management. This will allow medical providers to partner with their patients to develop an individualized bowel plan utilizing a combination of various pharmacological, mechanical and surgical interventions that prevent complications and ensure successful management and compliance. For people with SCI and neurogenic bowel dysfunction, the fundamental goal is to maintain health and well-being, promote a good quality of life and support active, fulfilled lives in their homes and communities.

Paracellular Filtration Secretion Driven by Mechanical Force Contributes to Small Intestinal Fluid Dynamics

Studies of fluid secretion by the small intestine are dominated by the coupling with ATP-dependent generation of ion gradients, whereas the contribution of filtration secretion has been overlooked, possibly by the lack of a known mechanistic basis. We measured apical fluid flow and generation of hydrostatic pressure gradients by epithelia of cultured mouse enterocytes, Caco-2 and T-84 cells, and fibroblasts exposed to mechanical force provided by vigorous aeration and in response to ion gradients, inhibitors of ion channels and transporters and in vitro using intact mouse and rat small intestine. We describe herein a paracellular pathway for unidirectional filtration secretion that is driven by mechanical force, requires tight junctions, is independent of ionic and osmotic gradients, generates persistent hydrostatic pressure gradients, and would contribute to the fluid shifts that occur during digestion and diarrhea. Zinc inhibits the flow of fluid and the paracellular marker fluorescein isothyocyanate conjugated dextran (MW = 4 kD) across epithelia of cultured enterocytes (>95%; p < 0.001) and intact small intestine (>40%; p = 0.03). We propose that mechanical force drives fluid secretion through the tight junction complex via a “one-way check valve” that can be regulated. This pathway of filtration secretion complements chloride-coupled fluid secretion during high-volume fluid flow. The role of filtration secretion in the genesis of diarrhea in intact animals needs further study. Our findings may explain a potential linkage between intestinal motility and intestinal fluid dynamics.

Feasibility of Low Fermentable Oligosaccharide, Disaccharide, Monosaccharide, and Polyol Diet and Its Effects on Quality of Life in an Italian Cohort

The low Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet has demonstrated excellent results in terms of symptom control and health-related quality of life (HRQoL) in irritable bowel syndrome (IBS) sufferers, but patients have complained about unsatisfying taste, difficulty in following the diet, and time consumption. To investigate the feasibility of the low FODMAP diet in an Italian (Sardinian) cohort, sixty consecutive eligible outpatients (11 men and 49 women) with IBS were enrolled and followed a low FODMAP diet (gluten allowed, restriction phase of four weeks, reintroduction phase of four weeks). Food habits were assessed using 24-hour dietary recall, Bristol Stool Scale for stool consistency, Visual Analogue Scale for abdominal bloating, VAS (Visual Analogue Scale) for abdominal pain, IBS Severity Scoring System for perceived disease severity, and a 12-item Short Form Survey for HRQoL (psychological component summary + mental component summary) were applied at baseline (T0) and at the end of each phase (T1-four weeks and T2-eight weeks). Statistical analysis was performed by dividing the cohort into diarrhoea-dominant IBS (IBS-D) and other IBS subtypes (selected IBS-others). Comparisons between T1 and T2 vs. T0 and T2 vs. T1 were performed. The low FODMAP diet lowered VASp (VAS pain), VASb (VAS bloating), and IBS SSS (IBS Severity Scoring System), and increased PCS (Physical Component Summary) and MCS (Mental Component Summary) in both subgroups. Bristol Stool Scale (BSS) only improved in the IBS-D subgroup. The dropout mean values for MCS were higher than treated subjects and the percentage of unemployment was lower in the dropouts. According to the dropout features, the low FODMAP diet seems to show greater feasibility for patients with more time to dedicate to the diet (unemployed, homemakers, housewives, or students), more motivation, and more severe clinical features, independent of their place of residence.

Managing autonomic dysfunction in Parkinson's disease: a review of emerging drugs

Introduction: Autonomic dysfunction is an integral part of Parkinson disease (PD) complex and can be seen both in early and advanced stages. There is a paucity of medicines available to manage autonomic dysfunction in PD and this adds to the considerable morbidity associated with the illness.Areas covered: The pathophysiology and the available therapeutic options of autonomic dysfunction seen in PD are discussed in detail. The potential targets for novel regimens are reviewed and the available literature on the drugs emerging in management of autonomic dysfunction in PD is highlighted.Expert opinion: In the current scenario, there are several drugs that can be tried for constipation viz stool laxatives, prucalopride, prokinetic agents and a high fiber diet. Bladder dysfunction has been treated with β-agonists and with mirabegron, a selective β-3 agonist, the anticholinergic side effects are minimized, and the drug has been found to be effective. Orthostatic hypotension is managed with midodrine while droxidopa is a new drug with promising efficacy. Botulinum toxin works best for management of sialorrhea, but repeated injections are needed.

Effect of Lubiprostone on Urinary Protein Excretion: A Report of Two IgA Nephropathy Patients with Chronic Constipation

Disturbance of the normal gut microbiota has been implicated in the pathogenesis of various diseases, including chronic kidney disease (CKD). A common CKD symptom is chronic constipation. Lubiprostone is a safe and efficacious drug for treating chronic constipation. We herein report 2 patients with IgA nephropathy treated with lubiprostone (24 μg 1×/day). The lubiprostone treatment ameliorated their chronic constipation and, unexpectedly, reduced the urinary protein excretion, urinary liver-type fatty acid binding protein and urine occult blood. These results may indicate that lubiprostone is a useful therapeutic intervention against the progression of IgA nephropathy with chronic constipation.

Long-term outcome after segmental colonic resection for slow transit constipation

PURPOSE

Colectomy with ileorectal anastomosis (IRA) is the most common surgical procedure for slow transit constipation (STC). A hemicolectomy has been suggested as an alternative to IRA with good short-term results. However, long-term results are unknown. The aim of this study was to evaluate the long-term results after hemicolectomy as a treatment for STC.

METHODS

Fifty patients with STC were selected for right- or left-sided hemicolectomy after evaluation with colonic scintigraphy from 1993 to 2008. Living patients (n = 43) received a bowel function questionnaire and a questionnaire about patient-reported outcome.

RESULTS

After a median follow-up of 19.8 years, 13 patients had undergone rescue surgery (n = 12) or used irrigation (n = 1) and were classified as failures. In all, 30 were evaluable for functional outcome and questionnaire data for 19 patients (due to 11 non-responding) could be analysed. Two reported deterioration after several years and were also classified as failures. Median stool frequency remained increased from 1 per week at baseline to 5 per week at long-term follow-up (p = 0.001). Preoperatively, all patients used laxatives, whereas 12 managed without laxatives at long-term follow-up (p = 0.002). There was some reduction in other constipation symptoms but not statically significant. In the patients' global assessment, 10 stated a very good result, seven a good result and two a poor result.

CONCLUSIONS

Hemicolectomy for STC increases stool frequency and reduces laxative use. Long-term success rate could range between 17/50 (34%) and 35/50 (70%) depending on outcome among non-responders.

DA-9701 improves colonic transit time and symptoms in patients with functional constipation: A prospective study

BACKGROUND AND AIM

DA-9701, a newly developed prokinetic agent formulated with Pharbitis Semen and Corydalis Tuber, has been shown to effectively treat functional dyspepsia. Recently, it has also been suspected to improve gastrointestinal motor function. The aims of this study were to assess the effect of DA-9701 on colonic transit time (CTT) and symptoms of functional constipation.

METHODS

Thirty-three patients with functional constipation based on the Rome III criteria were prospectively enrolled. The patients received 30-mg DA-9701 three times a day for 24 days. CTT was estimated initially and at the end of treatment. Symptoms such as spontaneous bowel movements, straining, stool form, feeling of incomplete emptying and anorectal blockage, abdominal discomfort and pain, overall defecation satisfaction, and incidence of adverse events were also analyzed.

RESULTS

Twenty-seven patients completed the study. DA-9701 was associated with a significantly reduced CTT from 34.9 ± 17.6 to 23.7 ± 19.1 h (P = 0.001). Segmental CTT also significantly decreased after treatment (right CTT: from 16.8 [0.0-28.8] to 6.0 [0.0-25.2] hours, P < 0.001; rectosigmoid transit time: from 13.2 [0.0-38.4] to 6.0 [0.0-33.6] hours, P = 0.021). In addition, all constipation-related subjective symptoms, including spontaneous bowel movement frequency, significantly improved compared with those before treatment. Serious adverse events did not occur.

CONCLUSIONS

DA-9701 accelerates colonic transit and safely improves symptoms in patients with functional constipation. Therefore, we suggest that this novel agent could help to treat patients with this condition.

A Randomized Phase III Clinical Trial of Plecanatide, a Uroguanylin Analog, in Patients With Chronic Idiopathic Constipation

OBJECTIVES

This study assessed the efficacy and safety of plecanatide, a guanylate cyclase-C (GC-C) agonist and the first uroguanylin analog approved for the treatment of chronic idiopathic constipation (CIC).

METHODS

This phase III, multicenter, double-blind, placebo-controlled study randomized 1,394 patients with CIC. Patients received either plecanatide (3 or 6 mg) or placebo, orally, once daily, for 12 weeks. The primary efficacy endpoint was the percentage of patients who were durable overall complete spontaneous bowel movement (CSBM) responders over the 12-week treatment period. Patients were instructed to record their daily bowel movements, stool consistency scores, and abdominal symptoms in an electronic diary. Treatment-emergent adverse events (AEs) were collected.

RESULTS

Each dose of plecanatide resulted in a significantly greater percentage of durable overall CSBM responders (21.0%, 3 mg; 19.5%, 6 mg) as compared with placebo (10.2%; P<0.001 for both). Plecanatide (3 and 6 mg) also significantly increased mean weekly CSBM frequency from baseline (increase of 2.5 and 2.2/week, respectively) vs. placebo (1.2/week; P<0.001 for both) and mean weekly spontaneous bowel movement frequency (increase of 3.2 and 3.1/week, respectively) vs. placebo (1.3/week; P<0.001, for both) over the 12-week treatment period. Both plecanatide doses significantly improved all secondary and additional efficacy endpoints. The most common AE, diarrhea, occurred in 1.3% (placebo), 5.9% (3 mg) and 5.7% (6 mg) of patients.

CONCLUSIONS

Plecanatide significantly improved constipation and its related symptoms with a low rate of adverse events. These results suggest that plecanatide will be a useful treatment option in the management of CIC. ClinicalTrials.gov: NCT01982240.

Colonic Inertia: approach and treatment

Objective Revision of the state of the art of the knowledge regarding pathophysiology, diagnosis and treatment of Colonic Inertia, which predominantly affects young women and has a significant socio-economic impact.

Methods A search was made in “colonic inertia”, “colon inertia” and “slow transit constipation” in PubMed database for articles of the last 5 years, in Portuguese or English with available abstract and full text. 59 articles and 2013 guidelines of the American Gastroenterological Association on constipation were included.

Results The pathophysiology is not completely elucidated and the reduction of the interstitial cells of Cajal is the most consistent histological finding. Diagnosis requires the exclusion of secondary causes of constipation and obstructed defecation syndrome, to which contribute several complementary diagnostic tests. Given the frequency of failure of the medical treatment, surgery is often the only possible option. Sacral nerve stimulation seems to be a promising therapeutical alternative.

Conclusion A deeper investigation of the pathophysiological mechanisms is fundamental to acquire a more global and integrated vision. Rigorous patient selection for each treatment and the discovery of new therapeutical targets may avoid the use of surgical therapies.

Nanoconjugated NAP as a Potent and Periphery Selective Mu Opioid Receptor Modulator To Treat Opioid-Induced Constipation

Opioids are the mainstay for cancer and noncancer pain management. However, their use is often associated with multiple adverse effects. Among them, the most common and persistent one is probably opioid-induced constipation (OIC). Periphery selective opioid antagonists may alleviate the symptoms of OIC without compromising the analgesic effects of opioids. Recently our laboratories have identified one novel lead compound, 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-[(4'-pyridyl)acetamido]morphinan (NAP), as a peripherally selective mu opioid receptor ligand carrying subnanomolar affinity to the mu opioid receptor and over 100-folds of selectivity over both the delta and kappa opioid receptors, with reasonable oral availability and half-life, and potential to treat OIC. Nanoparticle-based drug delivery systems are now widely considered due to their technological advantages such as good stability, high carrier capacity, low therapeutic side effects, etc. Herein we report nanoparticle supported NAP as a potential candidate for OIC treatment with improved peripheral selectivity over the original lead compound NAP.

Gastrointestinal Manifestations of Systemic Sclerosis

In patients with systemic sclerosis (SSc), gastrointestinal (GI) tract involvement is almost universal. Any segment of the GI tract from mouth to anus can be involved, and GI symptoms are a frequent cause of morbidity. In severe cases, GI tract involvement can progress to the point of malnutrition requiring parenteral nutrition. GI tract involvement in SSc contributes to disease-related mortality although mostly as a co-morbidity rather than direct cause of death. The review is intended to help address challenges in the assessment and treatment of GI tract involvement in SSc.

Mast Cells and Irritable Bowel Syndrome: From the Bench to the Bedside

Irritable bowel syndrome (IBS) is traditionally defined as a functional disorder since it lacks demonstrable pathological abnormalities. However, in recent years, low grade inflammatory infiltration, often rich in mast cells, in both the small and large bowel, has been observed in some patients with IBS. The close association of mast cells with major intestinal functions, such as epithelial secretion and permeability, neuroimmune interactions, visceral sensation, and peristalsis, makes researchers and gastroenterologists to focus attention on the key roles of mast cells in the pathogenesis of IBS. Numerous studies have been carried out to identify the mechanisms in the development, infiltration, activation, and degranulation of intestinal mast cells, as well as the actions of mast cells in the processes of mucosal barrier disruption, mucosal immune dysregulation, visceral hypersensitivity, dysmotility, and local and central stress in IBS. Moreover, therapies targeting mast cells, such as mast cell stabilizers (cromoglycate and ketotifen) and antagonists of histamine and serotonin receptors, have been tried in IBS patients, and have partially exhibited considerable efficacy. This review focuses on recent advances in the role of mast cells in IBS, with particular emphasis on bridging experimental data with clinical therapeutics for IBS patients.

Mechanism Investigation of the Improvement of Chang Run Tong on the Colonic Remodeling in Streptozotocin-Induced Diabetic Rats

Previous study demonstrated that Chang Run Tong (CRT) could partly restore the colon remodeling in streptozotocin- (STZ-) induced diabetic rats. Here we investigated the mechanisms of such effects of CRT. Diabetes was induced by a single injection of 40 mg/kg of STZ. CRT was poured into the stomach by gastric lavage once daily for 60 days. The remodeling parameters were obtained from diabetic (DM), CRT treated diabetic (T1, 50 g/kg; T2, 25 g/kg), and normal (Con) rats. Expressions of advanced glycation end product (AGE), AGE receptor, transforming growth factor-β1 (TGF-β1), and TGF-β1 receptor in the colon wall were immunochemically detected and quantitatively analyzed. The association between the expressions of those proteins and the remodeling parameters was analyzed. The expressions of those proteins were significantly higher in different colon layers in the DM group (P < 0.05, P < 0.01) and highly correlated to the remodeling parameters. Furthermore, the expressions of those proteins were significantly decreased in the T1 group (P < 0.05, P < 0.01) but not in the T2 group (P > 0.05). The corrective effect on the expressions of those proteins is likely to be one molecular pathway for the improvement of CRT on the diabetes-induced colon remodeling.

Potential Causes and Present Pharmacotherapy of Irritable Bowel Syndrome: An Overview

BACKGROUND

Irritable bowel syndrome (IBS) is currently one of the most common disorders of the digestive system in the Western society. Almost 2 out of 10 people suffer from IBS with women being more affected than men. IBS is associated with abdominal pain, bloating and altered stool consistency and imposes a heavy burden for the affected patients.

SUMMARY

The pathophysiology of IBS remains elusive although potential causes have been suggested, such as a deranged brain-gut signaling, hypersensitivity of visceral sensory afferent fibers, bacterial gastroenteritis, small intestinal bacterial overgrowth (SIBO), genetic alterations and food sensitivity. Targets for the pharmacotherapy of IBS include the serotonergic and opioidergic system, and the microbial population of the gut. Alternative therapies like traditional Chinese medicine have shown some success in the combat against IBS. Key Messages: Many therapeutics for the treatment of IBS have emerged in the past; however, only a few have met up with the expectations in larger clinical trials. Additionally, the multifactorial etiology of IBS and its variety of cardinal symptoms requires an individual set of therapeutics. This review provides a short overview of potential causes and current pharmacological therapeutics and of additional and alternative therapies for IBS.

Emerging therapies for patients with symptoms of opioid-induced bowel dysfunction

Opioid-induced bowel dysfunction (OIBD) comprises gastrointestinal (GI) symptoms, including dry mouth, nausea, vomiting, gastric stasis, bloating, abdominal pain, and opioid-induced constipation, which significantly impair patients’ quality of life and may lead to undertreatment of pain. Traditional laxatives are often prescribed for OIBD symptoms, although they display limited efficacy and exert adverse effects. Other strategies include prokinetics and change of opioids or their administration route. However, these approaches do not address underlying causes of OIBD associated with opioid effects on mostly peripheral opioid receptors located in the GI tract. Targeted management of OIBD comprises purely peripherally acting opioid receptor antagonists and a combination of opioid receptor agonist and antagonist. Methylnaltrexone induces laxation in 50%–60% of patients with advanced diseases and OIBD who do not respond to traditional oral laxatives without inducing opioid withdrawal symptoms with similar response (45%–50%) after an oral administration of naloxegol. A combination of prolonged-release oxycodone with prolonged-release naloxone (OXN) in one tablet (a ratio of 2:1) provides analgesia with limited negative effect on the bowel function, as oxycodone displays high oral bioavailability and naloxone demonstrates local antagonist effect on opioid receptors in the GI tract and is totally inactivated in the liver. OXN in daily doses of up to 80 mg/40 mg provides equally effective analgesia with improved bowel function compared to oxycodone administered alone in patients with chronic non-malignant and cancer-related pain. OIBD is a common complication of long-term opioid therapy and may lead to quality of life deterioration and undertreatment of pain. Thus, a complex assessment and management that addresses underlying causes and patomechanisms of OIBD is recommended. Newer strategies comprise methylnaltrexone or OXN administration in the management of OIBD, and OXN may be also considered as a preventive measure of OIBD development in patients who require opioid administration.

Constipation in adults: diagnosis and management

OPINION STATEMENT

Symptoms of constipation occur at all ages, with the greatest prevalence in individuals older than 60 years of age. It is estimated that 35 million individuals suffer from constipation in the USA, but only a small number will ever be diagnosed. Patients identify constipation symptoms differently than physicians. Whereas a patient may define their constipation by symptoms of bloating, distension, feeling of incomplete evacuation, abdominal discomfort, hard stools, and excessive straining, physicians often interpret prolonged timing between movements as the most essential criteria. An evaluation of constipation begins with a focused history of a person's bowel habit, medications, diet, physical activity, and an anorectal examination. In the absence of alarm signs, diagnostic testing for constipation is not routinely recommended in the initial evaluation. First-line management includes lifestyle changes of increased physical activity, high-fiber diets, adequate fluid intake, and bowel management techniques such as a straight back sitting position, using known triggers to stimulate bowel contractions, and a foot stool to elevate knees above bottom during toileting. When refractory to initial management, patients should have anorectal manometry to assess outlet function; additional testing may be required. Biofeedback is an effective treatment option for dyssynergic defecation. A range of traditional and new pharmacologic therapies are available to remedy constipation, from stool softeners to agents that increase intestinal transit. Managing the primary and secondary causes of constipation, incorporating effective bowel management techniques, along with the judicious use of laxatives can reduce constipation symptoms and improve quality of life.