Recent advances in understanding and managing chronic constipation

How do probiotics alleviate constipation? A narrative review of mechanisms

Constipation is a common gastrointestinal condition, which may occur at any age and affects countless people. The search for new treatments for constipation is ongoing as current drug treatments fail to provide fully satisfactory results. In recent years, probiotics have attracted much attention because of their demonstrated therapeutic efficacy and fewer side effects than pharmaceutical products. Many studies attempted to answer the question of how probiotics can alleviate constipation. It has been shown that different probiotic strains can alleviate constipation by different mechanisms. The mechanisms on probiotics in relieving constipation were associated with various aspects, including regulation of the gut microbiota composition, the level of short-chain fatty acids, aquaporin expression levels, neurotransmitters and hormone levels, inflammation, the intestinal environmental metabolic status, neurotrophic factor levels and the body's antioxidant levels. This paper summarizes the perception of the mechanisms on probiotics in relieving constipation and provides some suggestions on new research directions.

Development and validation of a nomogram to predict the risk of constipation after lumbar interbody fusion surgery

INTRODUCTION

To understand the incidence of postoperative constipation and the risk factors of constipation in patients with lumbar interbody fusion, we constructed and verified the constipation risk prediction model, so as to provide reference for the prevention and treatment of postoperative constipation.

METHODS

The data of patients undergoing lumbar interbody fusion in our hospital were retrospectively analyzed from December 2021 to December 2022. According to postoperative constipation, the patients were divided into constipation group and non-constipation group. Univariate logistic regression analysis and multivariate logistic regression analysis were used to determine independent risk factors for postoperative constipation. Based on independent risk factors, a nomogram was developed to predict the risk of constipation after lumbar interbody fusion. The prediction performance was assessed using receiver operating characteristic curve (ROC), calibration curve and decision curve analysis (DCA). Finally, bootstrapping method for internal validation was further evaluated the nomogram.

RESULTS

A total of 282 patients participated in the study. 176 patients (62.41%) after lumbar interbody occurred constipation, and 106 patients were asymptomatic. Multivariate regression analysis showed independent risk factors, including the use of calcium channel blockers, polypharmacy, postoperative bed time, and constipation history. Multivariate regression analysis was used to establish the model. The C-index of the nomogram was 0.827 (95% CI 0.779-0.875), and the C-index of interval bootstrapping validation was 0.813 (95% CI 0.765-0.861), and the area under the AUC was 0.800. The nomogram showed good discrimination ability.

CONCLUSIONS

The use of calcium channel blockers, polypharmacy, postoperative bed time, and history of constipation are independent risk factors for postoperative constipation in patients undergoing lumbar interbody fusion. The constructed risk prediction model has good discriminative ability.

A Low FODMAP Diet Supplemented with L-Tryptophan Reduces the Symptoms of Functional Constipation in Elderly Patients

(1) Background: The elderly suffer from functional constipation (FC), whose causes are not fully known, but nutritional factors may play a role. The aim of the present study was to assess the effect of a low FODMAP diet supplemented with L-tryptophan (TRP) on its metabolism and symptoms of functional constipation in elderly patients. (2) Methods: This study included 40 people without abdominal complaints (Group I, controls) and 60 patients with FC, diagnosed according to the Rome IV Criteria (Group II). Two groups were randomly selected: Group IIA (n = 30) was qualified for administration of the low FODMAP diet, and the diet of patients of Group IIB (n = 30) was supplemented with 1000 mg TRP per day. The severity of abdominal symptoms was assessed with an abdominal pain index ranging from 1 to 7 points (S-score). The concentration of TRP and its metabolites, 5-hydroxyindoleacetic acid (5-HIAA), kynurenine (KYN), and 3-indoxyl sulfate (3-IS) in urine were determined using the LC-MS/MS method. (3) Results: In Group II, 5-HIAA concentration in urine was lower, and KYN and 3-IS concentrations were higher than in the control group. A negative correlation was found between the S-score and urinary concentration of 5-HIAA (p < 0.001), and 3-IS concentration was positively correlated with the S-score. However, the correlation between the S-score and 3-IS concentration was negative (p < 0.01). After a dietary intervention, 5-HIAA concentration increased in both groups, and the severity of symptoms decreased, but the decrease was more pronounced in Group IIB. (4) Conclusion: A low FODMAP diet supplemented with L-tryptophan has beneficial effects in elderly patients suffering from functional constipation.

Torreya grandis Kernel Oil Alleviates Loperamide-Induced Slow Transit Constipation via Up-Regulating the Colonic Expressions of Occludin/Claudin-1/ZO-1 and 5-HT3R/5-HT4R in BALB/c Mice

SCOPE

Torreya grandis kernel has traditionally been used to remove intestinal parasites and increases intestinal motility. However, the effect of Torreya grandis kernel oil (TKO) on constipation has not yet been investigated. Therefore, mouse model is used to investigate the effect of TKO on slow transit constipation (STC) and its possible mechanism.

METHODS AND RESULTS

The effects of TKO on intestinal motility of STC mice are evaluated by fecal weight, fecal water content, colon length, defecation test, and intestinal propulsion test. The mechanism of TKO alleviating STC is explored by detecting biochemical analysis, histological analysis, western blot, qRT-PCR, immunohistochemistry, and gut microbiota analysis. The results reveal that TKO effectively promotes defecation and intestinal motility, increases the level of endothelin-1, and restores the histopathological morphology of the colon under LOP pretreatment. The expression levels of occludin, claudin-1, and zonula occludens-1 (ZO-1) mRNA and protein are up-regulated in mice receiving TKO treatment. The colonic 5-hydroxytryptamine 3R/4R (5-HT3R/5-HT4R) expressions are also increased by TKO supplementation. Additionally, TKO rescues LOP-caused disorders of the gut microbiota.

CONCLUSION

Consumption of TKO is beneficial to STC recovery, and it can alleviate LOP-induced STC by up-regulating the colonic expressions of Occludin/Claudin-1/ZO-1 and 5-HT3R/5-HT4R.

Tryptophan Metabolism in Postmenopausal Women with Functional Constipation

Constipation belongs to conditions commonly reported by postmenopausal women, but the mechanism behind this association is not fully known. The aim of the present study was to determine the relationship between some metabolites of tryptophan (TRP) and the occurrence and severity of abdominal symptoms (Rome IV) in postmenopausal women with functional constipation (FC, n = 40) as compared with age-adjusted postmenopausal women without FC. All women controlled their TRP intake in their daily diet. Urinary levels of TRP and its metabolites, 5-hydroxyindoleacetic acid (5-HIAA), kynurenine (KYN), and 3-indoxyl sulfate (indican, 3-IS), were determined by liquid chromatography/tandem mass spectrometry. Dysbiosis was assessed by a hydrogen-methane breath test. Women with FC consumed less TRP and had a lower urinary level of 5-HIAA, but higher levels of KYN and 3-IS compared with controls. The severity of symptoms showed a negative correlation with the 5-HIAA level, and a positive correlation with the 3-IS level. In conclusion, changes in TRP metabolism may contribute to FC in postmenopausal women, and dysbiosis may underlie this contribution.

Luteolin ameliorates loperamide-induced functional constipation in mice

Functional constipation (FC) is one of the most common gastrointestinal disorders characterized by hard stools and infrequent bowel movements, which is associated with dysfunction of the enteric nervous system and intestinal motility. Luteolin, a naturally occurring flavone, was reported to possess potential pharmacological activities on intestinal inflammation and nerve injury. This study aimed to explore the role of luteolin and its functional mechanism in loperamide-induced FC mice. Our results showed that luteolin treatment reversed the reduction in defecation frequency, fecal water content, and intestinal transit ratio, and the elevation in transit time of FC models. Consistently, luteolin increased the thickness of the muscular layer and lessened colonic histopathological injury induced by loperamide. Furthermore, we revealed that luteolin treatment increased the expression of neuronal protein HuC/D and the levels of intestinal motility-related biomarkers, including substance P (SP), vasoactive intestinal polypeptide (VIP), and acetylcholine (ACh), as well as interstitial cells of Cajal (ICC) biomarker KIT proto-oncogene, receptor tyrosine kinase (C-Kit), and anoctamin-1 (ANO1), implying that luteolin mediated enhancement of colonic function and contributed to the anti-intestinal dysmotility against loperamide-induced FC. Additionally, luteolin decreased the upregulation of aquaporin (AQP)-3, AQP-4, and AQP-8 in the colon of FC mice. In summary, our data showed that luteolin might be an attractive option for developing FC-relieving medications.

Associations between intestinal microbiota, fecal properties, and dietary fiber conditions: The Japanese traditional medicine Junchoto ameliorates dietary fiber deficit-induced constipation with F/B ratio alteration in rats

Changes in the intestinal microbiota are known to occur in constipated patients. Dietary fiber restriction presents obstacles to appropriate defecation and affects fecal properties, but the relationship between fecal microbiota and fecal morphological properties remains obscure. Therefore, we examined the influence of fiber diets on the fecal microbiome and properties in rats, and the effectiveness of the Japanese traditional medicine Junchoto (JCT) in rats with fiber deficit-induced constipation. Rats were fed three different fiber diets with varying cellulose contents (0 %, FFD; 5 %, ND; 15 %, HFD), respectively, as follows: study 1: 21 days of feeding; study 2: 14 days of feeding followed by 7 days of ND (fiber normalization in all groups); study 3: FFD for 21 days, followed by JCT administration from 14 days. Fecal properties and 16S rRNA amplicon sequencing results were examined. We observed that the fecal frequency, dry weight, and length were increased, and water ratio were decreased in a cellulose dose-dependent manner. The difference in several kinds of fecal microbiota, but not the α-diversity Chao1 index and the Firmicutes/Bacteroidetes ratio (F/B ratio), between groups were observed. The change in fecal property in both the HFD and FFD groups was ameliorated with fiber normalization, accompanied by alteration of the Chao1 index and/or F/B ratio. JCT administration reversed the fecal morphological changes in FFD group, accompanied by F/B ratio increasing. In conclusion, short-term dietary changes modulated microbial homeostasis, which is linked to fecal property. JCT may alter the F/B ratio and improve fecal properties to facilitate easier excretion.

Prevention and Treatment of Side Effects of Immunotherapy for Bladder Cancer

Bladder cancer (BC) is one of the most important tumors of the genitourinary system, associated with high morbidity and mortality rates. Over the years, various antitumor treatments have been developed, and immunotherapy is one of the most effective methods. Immunotherapy aims to activate the body’s immune system to kill cancer cells. It has been established that immunotherapy drugs can be classified into “non-targeted” and “targeted” drugs depending on their site of action. Immunotherapy is reportedly effective for BC. Even though it can attack cancer cells, it can also cause the immune system to attack healthy cells, which can occur at any time during treatment and sometimes even after immunotherapy is stopped. Importantly, different types of immunotherapies can cause different side effects. Side effects may manifest themselves as signs or as symptoms. The prevention and treatment of side effects caused by immunotherapy is an important part of cancer patient management.

Mechanisms of Action of Current Pharmacologic Options for the Treatment of Chronic Idiopathic Constipation and Irritable Bowel Syndrome With Constipation

Multiple therapeutic agents are currently available for the treatment of chronic idiopathic constipation and irritable bowel syndrome with constipation. A better understanding of the mechanism of action of each treatment provides important insights into expected responses and is key to optimizing treatment outcomes. Some constipation treatments, such as stimulant laxatives, may increase bowel movement frequency but are ineffective at relieving, and may even exacerbate, abdominal symptoms. On the contrary, prescription treatments, such as the guanylyl cyclase-C agonists, for example, may improve bowel symptoms and reduce visceral hypersensitivity. This review summarizes the mechanisms of action of commonly used over-the-counter and prescription therapies for chronic idiopathic constipation and irritable bowel syndrome with constipation, outlining how these mechanisms contribute to the efficacy and safety of each treatment option.

Prokinetic and Laxative Effects of Chrozophora tinctoria Whole Plant Extract

Chrozophora tinctoria (Euphorbiaceae) has been used as an emetic, anthelminthic, and cathartic agent in traditional medicine. We used gas chromatography-mass spectrometry (GC-MS) to characterize the composition of ethyl acetate (EAC) and dichloromethane (DCMC) fractions from the whole Chrozophora tinctoria plant. EAC and DCMC fractions were evaluated for acetylcholinesterase (AChE) inhibitory activity and acute toxicity. Their effects on intestinal propulsive movement and spasmogenic activity of the gastrointestinal tract (GIT) muscle were also assessed. The compounds detected in both fractions were mostly fatty acids, with about seven compounds in EAC and 10 in DCMC. These included pharmacologically active compounds such as imipramine, used to treat depression, or hexadecanoic acid methyl ester, an antioxidant. Both EAC and DCMC fractions inhibited acetylcholinesterase (AChE) activity with IC₅₀ values of 10 µg and 130 µg, respectively. Both the fractions were found to be toxic in a dose-dependent manner, inducing emesis at 0.5 g or higher and lethargy and mortality from 3–5 g upwards. Similarly, both of the fractions showed laxative activity in metronidazole- and loperamide-induced constipation models. EAC relaxed the intestinal muscle at a lower dose (1 mg/mL) than DCMC. Similarly, the EAC extract showed a significant relaxation effect (EC₅₀ = 0.67 ± 0.15 mg/mL) on KCL-induced contraction in rabbit jejunum as compared to DCMC (EC₅₀ = 5.04 ± 0.05 mg/kg). The present study strongly supports the folklore that this valuable plant is a cathartic agent. Further work is required to isolate and validate the bioactive compounds that act as diarrheal agents in Chrozophora tinctoria.

Pharbitis nil extract ameliorates functional constipation and intestinal microflora disorder induced by loperamide in rats

BACKGROUND

Semen pharbitidis can be used for the treatment of constipation; however, the specific pharmacological effect and mechanism of its main pharmacological active ingredient pharbitis nil extract (PN) on functional constipation (FC) are still not clear.

AIM

To investigate the regulatory effect of PN on constipation symptoms, intestinal motility, colonic myoelectric activity, colonic tissue morphology, intestinal microflora and neurotransmitters in FC rats.

METHODS

A rat model of FC was established by intragastric administ-ration of loperamide (Lop) and then treated with PN. The number of fecal pellets within 6 h, fecal water content, intestinal transit rate, and colonic myoelectric activity were observed and recorded. The alteration of intestinal flora was measured by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Hematoxylin-eosin (H&E) staining was used to detect the morphological changes of colon tissues. The expression levels of vasoactive intestinal peptide (VIP), substance P (SP), and 5-hydroxytryptamine (5-HT) were determined by enzyme linked immunosorbent assay (ELISA).

RESULTS

PN could significantly increase the fecal pellet count and water content within 6 h, accelerate the intestinal ink propelling rate, and decrease the frequency and amplitude variation of colon myoelectric activity in FC rats. H&E staining showed that PN improved the colon histological changes induced by Lop. PCR-DGGE demonstrated that PN rectified the abundance of Bacteroidetes and Verrucomicrobia and increased the abundance of Lactobacillaceae and Bifidobacteriaceae in FC rats. ELISA showed that PN significantly increased the SP and 5-HT expression and decreased the expression of VIP in colon tissues of FC rats.

CONCLUSION

PN alleviates FC caused by Lop and improves intestinal microflora and intestinal nervous system.

Preclinical experimental models for assessing laxative activities of substances/products under investigation: a scoping review of the literature

Constipation is a common gastrointestinal problem worldwide. Its impact on health can range from an unpleasant problem to being seriously troublesome. When lifestyle modification fails to deal with constipation, laxatives are the mainstay of therapy. There are several types of laxatives currently available; however, there still remains a need for better laxatives because certain currently available laxatives are not appropriate for or accessible to some patients. Preclinical experiments to study the laxative potential of substances/products of interest are vital to improving that situation. The selection of appropriate experimental models for assessing the laxative activities of substances/products under investigation is crucial to achieving valid and meaningful results. This article provides a scoping review of the literature, outlining, and summarizing models currently being used in preclinical experiments assessing the laxative activities of substances/products under investigation. The review includes both screening models, e.g., the isolated organ bath system, in vivo fecal assessment and intestinal transit assay, and confirmation models, e.g., in vivo constipation models. Chemical substances/drugs used to induce constipation in in vivo constipation models, e.g., loperamide, diphenoxylate, montmorillonite, and clonidine, as well as standard laxative agents used as a positive control in experimental models, e.g., bisacodyl, carbachol, lactulose, sodium picosulfate, castor oil, phenolphthalein, and yohimbine, are described in detail. The purpose of this article is to assist researchers in the design and implementation of preclinical experimental models for assessing laxative activities of substances/products under investigation to achieve valid and meaningful preclinical results prior to experimentation in humans.

Efficacy and Safety of Maxing Xianchang Su in the Treatment of Functional Constipation: A Randomized Controlled Trial

Background

Functional constipation (FC) is one of the prevalent gastrointestinal disorders that affect people of all ages. Long-term FC has significant effects on the quality of life of patients. Although commonly used drugs have reliable short-term effects, they are easily addictive and have side effects. Therefore, pursuing a convenient drug-food homogenous program is critical for FC patients. Maxing Xianchang Su is a functional food based on traditional Chinese medicine. To investigate the efficacy and safety of Maxing Xianchang Su in FC treatment, we conducted a randomized controlled trial.

Methods

We carried out a prospective multicenter randomized parallel controlled study in three hospitals in Jiangsu Province, China, from January 2020 to March 2021, which included 206 FC patients. All patients were arbitrarily assigned into a treatment group and a control group at a ratio of 1 : 1; 103 cases in each group. The treatment group was given oral Maxing Xianchang Su, whereas the control group was treated with lactulose oral solution. The course of treatment was two weeks. The two groups of patients were evaluated after six weeks for symptom improvement before and after taking the drug. Furthermore, the safety of Maxing Xianchang Su was assessed.

Results

Both groups of patients successfully completed the study without shedding cases. The effective rates of the treatment group and control group after two weeks were 90.6% and 67.0%, respectively. The treatment group had a better curative effect than the control group (P < 0.05). The symptom score of the two groups improved compared with that before the treatment. The difference between the two groups was statistically significant (P < 0.05). During the treatment process, neither group experienced abnormal changes in blood lipid, blood glucose, routine hematuria, or liver and kidney functions. There were no adverse reactions in both groups.

Conclusion

Maxing Xianchang Su has a positive effect on FC treatment with reliable mid-term effect and a high level of safety.

Efficacy and safety of lubiprostone for the treatment of functional constipation in Chinese adult patients: A multicenter, randomized, double-blind, placebo-controlled trial

OBJECTIVES

Functional constipation is a gastrointestinal disorder prevalent around the world. Lubiprostone is the first locally acting type-2 chloride channel activator to be used for treating constipation. This study aimed to evaluate the efficacy and safety of lubiprostone in Chinese adults with functional constipation.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled study. Patients with functional constipation were randomized to receive either lubiprostone (24 mcg twice daily) or placebo for 4 weeks. The primary end-point was the frequency of spontaneous bowel movements (SBMs) during the first week of treatment. The secondary end-points included the median time of the first SBM, SBM frequency at weeks 2, 3 and 4, weekly response rate of SBMs, the stool consistency score and average number of complete spontaneous bowel movements (CSBMs) per week.

RESULTS

In total, 259 patients were randomized, with 130 in the lubiprostone group and 129 in the placebo group. SBM frequency was higher in the lubiprostone group (4.88 ± 4.09/wk) than that in the placebo group (3.22 ± 2.01/wk) at week 1 (P < 0.0001). SBM frequency was also higher in the lubiprostone group at weeks 2, 3 and 4. The average number of CSBMs and the stool consistency score in the lubiprostone group were significantly higher than that in the placebo group at each week. No drug-related serious adverse events (AEs) occurred. The most commonly reported AE was nausea.

CONCLUSION

Lubiprostone was superior to placebo in treating Chinese patients with functional constipation, together with good safety profile.

Roles of Gut Microbiota and Metabolites in Pathogenesis of Functional Constipation

Functional constipation (FC), a condition characterized by heterogeneous symptoms (infrequent bowel movements, hard stools, excessive straining, or a sense of incomplete evacuation), is prevalent over the world. It is a multifactorial disorder and can be categorized into four subgroups according to different pathological mechanisms: normal transit constipation (NTC), slow transit constipation (STC), defecatory disorders (DD), and mixed type. Recently, growing evidence from human and animals has pointed that there was a strong association between gut microbiota and FC based on the brain-gut-microbiome axis. Studies have reported that the main characteristics of gut microbiota in FC patients were the relative decrease of beneficial bacteria such as Lactobacillus and Bifidobacterium, the relative increase of potential pathogens, and the reduced species richness. Gut microbiota can modulate gut functions through the metabolites of bacterial fermentation, among which short-chain fatty acids (SCFAs), secondary bile salts (BAs), and methane occupied more important positions and could trigger the release of gut hormones from enteroendocrine cells (EECs), such as 5-hydroxytryptamine (5-HT), peptide YY (PYY), and glucagon-like peptide-1 (GLP-1). Subsequently, these gut hormones can influence gut sensation, secretion, and motility, primarily through activating specific receptors distributed on smooth muscle cells, enteric neurons, and epithelial cells. However, research findings were inconsistent and even conflicting, which may be partially due to various confounding factors. Future studies should take the associated confounders into consideration and adopt multiomics research strategies to obtain more complete conclusions and to provide reliable theoretical support for exploring new therapeutic targets.

The effect of sodium carboxymethyl starch with high degree of substitution on defecation

Sodium carboxymethyl starch (CMS-Na), a kind of food additive with high degree of substitution, is also known as a prebiotic. The aim of this study was to determine the effect of CMS-Na on defecation. Constipated mouse model was prepared by loperamide. Normal rats were also used in the study. Short-chain fatty acids in rat feces were detected by gas chromatography. The bacterial communities in rat feces were identified by 16S rDNA gene sequencing. 5-hydroxytryptamine (5-HT) and tryptophan hydroxylase 1 (Tph1) were measured by ELISA. The results showed that CMS-Na increased the fecal granule counts and intestinal propulsion rate in constipated mice. The contents of water, acetic acid, propionic acid and n-butyrate in feces, Tph1 in colon and 5-HT in serum of rats were increased. In addition, CMS-Na shortened the colonic transport time in rats. The 16S rDNA gene sequencing results indicated that CMS-Na increased the relative abundance of Alloprevotella and decreased the proportion of Lactobacillus. However, the biodiversity of the normal intestinal flora was not altered. In conclusion, CMS-Na can promote defecation in constipated mice. The mechanism may be related to the regulation of Alloprevotella and Lactobacillus in colon, the increase of short-chain fatty acids, and the promotion of the synthesis of Tph1 and 5-HT.

Prevalence and risk factors of functional constipation in the Rome IV criteria during a medical check-up in Japan

BACKGROUND AND AIM

Functional constipation (FC) is one of the functional bowel disorders with symptoms of constipation in the Rome IV criteria. This study aimed to examine the epidemiology of FC in a large-scale survey of individuals undergoing a medical check-up in Japan.

METHODS

A total of 13 729 subjects who underwent a medical check-up at MedCity21 between April 2018 and March 2019 were given a questionnaire that inquired about bowel habits. Among them, 10 658 subjects participated in this study, and FC was diagnosed based on the Rome IV criteria.

RESULTS

The number of subjects who fulfilled diagnostic criteria of FC was 220, and the prevalence of FC was 2.1%. Compared with subjects with non-FC, those with FC were more complaining of abdominal bloating and distension, feeling stressed, getting annoyed, lack of motivation, fatigue upon waking, and feeling depressed. The risk of FC was significantly lower among subjects who drank alcohol more than 5 days a week, exercised for more than 30 min at least twice a week for more than 1 year, and were getting enough rest by sleeping, whereas it was significantly higher among women and subjects who were eating faster than other people.

CONCLUSIONS

The prevalence of FC in Japanese subjects during a medical check-up was relatively low compared with that in Western countries. Subjects with FC had troublesome symptoms, and it might be suggested that female sex, lack of regular exercise with moderate activity, insufficient rest by sleeping, and eating faster were a risk of FC.

Review article: diagnosis, management and patient perspectives of the spectrum of constipation disorders

BACKGROUND

Chronic constipation is a common, heterogeneous disorder with multiple symptoms and pathophysiological mechanisms. Patients are often referred to a gastroenterology provider after laxatives fail. However, there is limited knowledge of the spectrum and management of constipation disorders.

AIM

To discuss the latest understanding of the spectrum of constipation disorders, tools for identifying a pathophysiologic-based diagnosis in the specialist setting, treatment options and the patient's perspective of constipation.

METHODS

Literature searches were conducted using PubMed for constipation diagnostic criteria, diagnostic tools and approved treatments. The authors provided insight from their own practices.

RESULTS

Clinical assessment, stool diaries and Rome IV diagnostic criteria can facilitate diagnosis, evaluate severity and distinguish between IBS with constipation, chronic idiopathic constipation and dyssynergic defecation. Novel smartphone applications can help track constipation symptoms. Rectal examinations, anorectal manometry and balloon expulsion, assessments of neuromuscular function with colonic transit time and colonic manometry can provide mechanistic understanding of underlying pathophysiology. Treatments include lifestyle and diet changes, biofeedback therapy and pharmacological agents. Several classes of laxatives, as well as prokinetic and prosecretory agents, are available; here we describe their mechanisms of action, efficacy and side effects.

CONCLUSIONS

Constipation includes multiple overlapping subtypes identifiable using detailed history, current diagnostic tools and smartphone applications. Recognition of individual subtype(s) could pave the way for optimal, evidence-based treatments by a gastroenterology provider.

The combined therapy of fecal microbiota transplantation and laxatives for functional constipation in adults: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Functional constipation is a prevalent, burdensome gastrointestinal disorder whose treatment remains challenging. Combined therapy uniting multiple treatments may be promising. Fecal microbiota transplantation (FMT) which tends to be an etiological treatment has been increasingly investigated in its management. Meanwhile, laxatives are widely used to relieve constipation temporarily, but their overall efficacy is poor. Therefore, we performed meta-analyses of randomized controlled trials to evaluate the joint efficacy of FMT and laxatives in functional constipation.

METHODS

We performed a systematic literature search of 6 electronic databases as of August 11, 2020. Randomized controlled trial of FMT together with laxatives vs laxatives alone in functional constipation in adults were included. Two reviewers independently performed the screening, data extraction, and bias assessment. Dichotomous outcome data were synthesized by risk ratio, and measurement data by weighted mean difference (WMD).

RESULTS

A total of 1400 records were identified, of which 5 were eligible (409 patients). Overall, compared to laxatives alone, combined therapy of FMT and laxatives more significantly improved total effective rate (risk ratio: 1.35; 95% confidence interval [CI]: 1.14, 1.60; I2 = 13%), Bristol stool form scale score (WMD: 1.04; 95% CI: 0.57, 1.51; I2 = 76%), reduce Wexner score (WMD: -3.25; 95% CI: -5.58, -0.92; I2 = 92%), Knowles-Eccersley-Scott-Symptom (KESS) score (WMD: -5.65; 95% CI: -7.62, -3.69; I2 = 0%) and patient assessment of constipation quality of life score (WMD: -18.56; 95%; CI: -26.43, -10.68; I2 = 78%). No serious adverse events were reported. The majority of included studies had poor methodological quality.

CONCLUSION

Combined therapy of FMT and laxatives may be a reasonably effective and safe treatment for people with functional constipation. However, caution is needed with the interpretation of these data due to the small sample size, high heterogeneity, and low quality of the studies. Besides, we expect that more studies will be performed exploring the efficacy and safety of combined therapy for functional constipation.

Colonic 5-HT4 receptors are targets for novel prokinetic drugs

5-HT₄ receptors are G protein-coupled receptors that link to the stimulatory protein Gs which activates adenylate cyclase to increase intracellular cyclic AMP which then activates protein kinase A (PKA). 5-HT₄ receptors are expressed by neurons in the central and peripheral nervous systems especially the enteric nervous system (ENS). In general, 5-HT₄ receptors are stimulatory and their activation in the ENS enhances neurotransmitter release and propulsive motility patterns. 5-HT₄ receptors are expressed by enterochromaffin (EC) cells, Goblet cells, and most enteric neurons. The study by Konen and colleagues in this issue of Neurogastroenterology and Motility features two novel 5-HT₄ receptor agonists (5-HT₄ -LA1 and 5-HT₄ -LA-2) that are not absorbed from the gastrointestinal tract of mice and act locally in the colonic mucosa to stimulate propulsive motility. The authors show that 5-HT₄ -LA1 and 5-HT₄ -LA2 were not absorbed from the colon and that both drugs stimulated colonic transit when administered by gavage. Both agonists stimulated colonic glass bead expulsion, and 5-HT₄ LA1 activation stimulated fecal output and increased fecal water content. These effects were detected in young and aged mice. 5-HT₄ receptors were also localized to the epithelium of the human duodenum, ileum, and colon. These studies highlight novel 5-HT₄ receptor agonists that have prokinetic actions on the GI tract. These drugs are not absorbed and act locally in the gut mucosa to stimulate propulsive motility while minimizing access to systemic 5-HT₄ receptors and avoiding potential unwanted side effects.

Deciphering the correlations between aging and constipation by metabolomics and network pharmacology

From the points of view of phenomena and experience, aging and constipation are inextricably correlated. However, experimental support and underlying mechanisms are still lacking. The purpose of this study is to explore the relationships between aging and constipation from the perspectives of fecal metabolites and network pharmacology. The behavioral analyses of aging and constipation were carried out on both aging rats and constipation rats. We found that aging rats exhibited not only significant aging behaviors but also significant constipation behaviors, while constipation rats exhibited both significant constipation and aging behaviors. Additionally, fecal metabolomics was carried out and found that 23 metabolites were aging-related and 22 metabolites were constipation-related. Among them, there were 16 differential metabolites in common with 11 metabolic pathways. Network pharmacology was applied to construct the target-pathway network of aging and constipation, revealing that pathway in cancer was the most associated signaling pathway. The current findings will provide not only a novel perspective for understanding aging and constipation, but a theoretical association and understanding the traditional Chinese medicine theory and the Western medicine theory about aging and constipation, as well as support for the clinical research and development of medicine related to constipation in the elderly.

Clinical Evaluation of a Patient With Symptoms of Colonic or Anorectal Motility Disorders

Constipation, irritable bowel syndrome, fecal incontinence, abdominal pain, and anorectal pain are problems that affect 40% of the population. They commonly present with overlapping symptoms indicating that their pathophysiology affects multiple segments of the gut as well as brain and gut interactions. Clinically, although some conditions are readily recognized, dyssynergic defecation, fecal incontinence, and anorectal pain are often missed or misdiagnosed. Consequently, the assessment of lower gastrointestinal symptoms in patients with suspected colonic or anorectal motility disorder(s) remains challenging for most clinicians. A detailed history, use of the Bristol stool form scale, prospective stool diaries, ideally through a phone App, digital rectal examination, and judicious use of complementary diagnostic tests are essential. Additionally, it is important to evaluate the impact of these problems on quality of life and psychosocial issues, because they are intricately linked with these disorders. The Rome IV diagnostic questionnaire for functional gastrointestinal disorders can provide additional information often missed during history taking. Here, we discuss a systematic approach for the clinical evaluation of patients with suspected lower gastrointestinal problems, grouped under 4 common diagnostic categories. We describe how to take a detailed history, perform meticulous digital rectal examination, and use validated tools to supplement clinical evaluation, including assessments of quality of life and scoring systems for disease severity and digital Apps. These tools could facilitate a comprehensive plan for clinical management including diagnostic tests, and translate the patients' complaints into definable, diagnostic categories.

Is Constipation Associated with Worse Functioning in Adult Women? A Cross-Sectional Study

OBJECTIVE

The aim of this study is to analyze the relationship between intestinal constipation and functioning in adult women living in a municipality in the interior of northeast Brazil.

MATERIALS AND METHODS

This is a cross-sectional study conducted with 195 adult women in the city of Santa Cruz-RN. Constipation was diagnosed using the Rome III criteria. Functioning was measured through WHODAS 2.0. Social conditions, habits and lifestyle were also investigated. Inferential analysis was performed using the chi-squared test and the Mann-Whitney U-test, and the effect size was determined by eta squared (η2). Multivariate analysis was performed using multiple linear regression to analyze the relationship between the WHODAS total score and constipation, being adjusted by covariates with p≤0.20 in the bivariate. A statistical significance level of p<0.05 was considered.

RESULTS

Most of the participants in this study were aged 19 to 39 years (69.7%) and had an income of up to 1 minimum monthly salary (79.5%). WHODAS scores showed that women with constipation had more disability in the cognitive (p <0.001), mobility (p <0.002), self-care (p <0.001), and participation (p <0.001) domains, as well as the total score (p <0.001). After multiple linear regression analysis, the total WHODAS score remained associated with constipation (p <0.001), in which this condition increases the score by nine points.

CONCLUSION

The results of this study show that there is a reduction in functioning associated with the presence of constipation in adult women, mainly affecting the cognition, mobility, self-care and participation domains, in addition to the total score.

Pharmacokinetics, Bioequivalence, and Safety Studies of Prucalopride in Healthy Chinese Subjects

The objectives of the present study were to evaluate the bioequivalence of 2 tablet formulations of prucalopride, generic and branded, and to investigate relevant pharmacokinetic and safety profiles. This study was designed as a randomized, open-label, fasting, single-dose, crossover, and dual-period trial. After overnight fasting, 12 subjects were given prucalopride tablets via oral administration, and blood specimens were obtained up to 96 hours after dosing. Prucalopride concentrations in plasma were measured using ultraprecision liquid chromatography-tandem mass spectrometry followed by calculation of pharmacokinetic parameters. The safety of prucalopride was assessed throughout the study. The pharmacokinetics of prucalopride can be defined as a 2-compartment model with a long elimination phase. No significant differences were observed between the pharmacokinetic profiles of the generic and branded prucalopride tablets. Bioequivalence was evaluated using 90%CIs for the ratio test/reference of log area under the concentration-time curve over 96 hours, log area under the concentration-time curve to infinity, and log peak concentration from generic and branded tablets, which were 100.06-109.94%, 100.63-110.32%, and 95.84-113.08%, respectively. During administration of the medication, there were 18 adverse events in 6 subjects in the test formulation group and 19 cases of adverse events in 6 subjects in the reference formulation group (P > .05). No severe adverse effects were detected. These results suggest that generic and branded prucalopride tablets are bioequivalent and show similar safety profiles.

Daikenchuto, a traditional Japanese herbal medicine, promotes colonic transit by inducing a propulsive movement pattern

BACKGROUND

The traditional Japanese herbal medicine, daikenchuto (DKT), has been used to treat constipation and postoperative ileus. However, the precise mechanisms involved in the pharmacological effects of DKT remain uncertain. The aim of this study was to clarify the effect of DKT on motor patterns and transit activity in the isolated rat colon.

METHODS

The entire colon or segments of the proximal colon in rats were isolated and placed in Krebs solution. The motility of the colon was evaluated by analyzing spatiotemporal maps of diameter derived from video imaging and measuring the intraluminal pressure in the anal end of the proximal colon, and the transit time of a plastic bead through the entire isolated colon.

KEY RESULTS

Several types of propagating contractions were observed in the isolated entire colon. When DKT was added to Krebs solution, the frequency of large-extent anal propagating contractions increased. DKT treatment increased the intraluminal pressure in the isolated proximal colon, which was related to the propagating contractions. This effect was abolished by treatment with the neural blocker tetrodotoxin. These findings suggest DKT induced peristaltic contractions in the isolated colon. DKT accelerated colonic transit activity, which was related to peristaltic contractions induction in the colon. These effects were also observed in the colons treated with bethanechol and the active ingredient of DKT, hydroxy-α-sanshool.

CONCLUSIONS AND INFERENCES

Daikenchuto could enhance colonic transit activity by inducing peristaltic contractions, which may be mediated by the activation of the enteric nervous system in the colon.

Plecanatide for the treatment of chronic idiopathic constipation in adult patients

Introduction. Chronic idiopathic constipation (CIC) is a functional gastrointestinal disorder that is associated with an increased healthcare cost and an abnormally poor quality of life. Plecanatide is a natural analog to the peptide agonist of the guanylate cyclase-C (GC-C) receptor, uroguanylin. The conversion of guanosine 5-triphosphate to cyclic guanosine monophosphate results in an increased bowel fluid secretion. Plecanatide is a promising new agent for CIC unresponsive to current therapeutic regimes.Areas covered. A comprehensive online search of Medline and the Science Citation Index was made using the keywords 'plecanatide', 'guanylate cyclase-C agonists', and 'constipation', in various combinations. We reviewed the pharmacodynamics, pharmacokinetics, and metabolism of this agent, and the most significant studies regarding the clinical efficacy and safety of plecanatide in CIC therapy.Expert opinion. Experimental studies showed that plecanatide was significantly better than placebo in reducing CIC severity, straining, stool consistency, bowel movements and quality of life. Apart from limited cases of diarrhea, no serious adverse events were reported. However, few data are available on its long-term safety. Furthermore, patients' affordability of plecanatide can be limited by its costs. Finally, this new agent with a different way of action can be proposed in patients refractory to common therapy.