Chronic severe constipation: current pathophysiological aspects, new diagnostic approaches, and therapeutic options

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.

Psychometric evaluation of the Chinese version of the Elderly-Constipation Impact Scale: a translation and validation study

OBJECTIVE

The objective of this study was to translate the Elderly-Constipation Impact Scale into Chinese and to examine its reliability and validity in a population of older people suffering from chronic constipation.

METHODS

In this study, the scale was paraphrased, back-translated, cross-culturally adapted and pre-experimented using the Brislin double translation-back-translation method to create the initial Chinese version of the Elderly-Constipation Impact Scale. A convenience sampling method was used to select 564 study participants who met the inclusion and exclusion criteria in Liaoning and Shanxi, China, to evaluate the reliability and validity of the scale. General information about the study population was using descriptive statistics; item analysis was used to screen the items of the scale. Content validity, exploratory factor analysis, and validation factor analysis were chosen to validate the scales; internal consistency, spilt-half reliability and retest reliability were used determine the reliability of the measurement scales.

RESULTS

The Chinese version of the Elderly-Constipation Impact Scale contains 7 dimensions and 21 items. The Cronbach's alpha coefficient for the total scale was 0.901 and the range of Cronbach's alpha values for each dimension was 0.707 to 0.918. The split-half reliability of the scale was 0.736 and the retest reliability was 0.763. The exploratory factor analysis showed a KMO value of 0.873 and a Bartlett's spherical test X² value of 3499.978 (p < 0.001). A total of seven common factors were extracted, namely daily activities, treatment satisfaction, lack of control of bodily function, diet restriction, symptom intensity, anxiety and preventive actions, with a cumulative variance contribution of 77.813%. Each item had a loading value > 0.4 on its common factor. In the validation factor analysis, the model fit results were X² / df = 1.886, GFI = 0.910, AGFI = 0.874, PGFI = 0.654, IFI = 0.955, TLI = 0.942, CFI = 0.954, RMSEA = 0.056 and PNFI = 0.718. The model fit indicators were all within acceptable limits.

CONCLUSION

The Chinese version of the E-CIS has good reliability and validity in the chronic constipation population of elderly individuals. The results of the questionnaire can effectively and comprehensively reflect the impact of chronic constipation on the quality of life of elderly individuals. It provides a meaningful reference for identifying targets for intervention.

Regulation of enteric nervous system via sacral nerve stimulation in opioid-induced constipated rats

Objectives

Sacral nerve stimulation (SNS) has been employed for treating constipation. However, its mechanisms involving enteric nervous system (ENS) and motility are largely unknown. In this study, we investigated the possible ENS involvement of SNS in treating Loperamide-induced constipation in rats.

Methods

Experiment-1 was designed to study the effects of acute SNS on whole colon transit time (CTT). In experiment-2, we induced constipation by Loperamide and then applied daily SNS or sham-SNS for 1 week. Choline acetyltransferase (ChAT), nitric oxide synthase (nNOS), and PGP9.5 in colon tissue were examined at the end of the study. Moreover, survival factors such as phosphorylated AKT (p-AKT) and Glial cell-derived neurotrophic factor (GDNF) were measures by immunohistochemistry (IHC) and western blot (WB).

Key results

(1) SNS with one set of parameters shortened CTT starting at 90 min after phenol red administration (p < 0.05). (2) While Loperamide induced slow transit constipation with a significant reduction in fecal pellet number and feces wet weight, daily SNS for a week resolved constipation. (3) Moreover, SNS was able to shorten whole gut transit time comparing to sham-SNS (p = 0.01). (4) Loperamide reduced the number of PGP9.5 and ChAT positive cells, and downregulated ChAT protein expression and upregulated nNOS protein expression, whereas these detrimental effects were significantly reversed by SNS. (5) Furthermore, SNS increased expressions of both GDNF and p-AKT in colon tissue. (6) Vagal activity was reduced following Loperamide (p < 0.01); yet SNS normalized vagal activity.

Conclusion

SNS with appropriate parameters improves opioid-induced constipation and reversed the detrimental effects of Loperamide on enteric neurons possibly via the GDNF-PI3K/Akt pathway.GRAPHICAL ABSTRACT.

Effectiveness of electroacupuncture versus prucalopride for women with severe chronic constipation: secondary analysis of a randomized controlled trial

PURPOSE

Electroacupuncture (EA) is a component alternative therapy for severe chronic constipation (SCC). Women are more vulnerable to SCC and gender might impact the response of patients with functional gastrointestinal disorders to therapy. We performed this secondary analysis to explore the effectiveness and safety of EA compared with prucalopride among women with SCC.

METHODS

Based on a multicenter, randomized, noninferiority trial, 446 female patients were randomly assigned to receive 28-session EA (n = 222) over 8 weeks with 24-week follow-up without treatment or to receive prucalopride (n = 224) over 32 consecutive weeks. The primary outcome was the proportion of overall complete spontaneous bowel movements (CSBMs) responders over weeks 1-8, defined as at least three CSBMs per week, and more than an increase of one CSBM from baseline meanwhile for at least 6 weeks during an 8-week treatment period. Secondary outcomes measure sustained CSBM responder, weekly responders, change from baseline in mean weekly CSBMs and SBMs, straining and stool consistency, quality of life, and adverse events (AEs).

RESULTS

The proportion of overall responders was 25.23% in the EA group, similar to 25.89% in the prucalopride group, with a between-group difference of - 0.67% (95% CI, - 8.80 to 7.40%; P = 0.872) during an 8-week treatment. In the secondary outcomes, EA and prucalopride groups had no significant difference, except that EA was inferior to prucalopride in improving SBMs. The AEs were less in the EA group than the prucalopride group.

CONCLUSION

EA may be a promising and safe treatment for women with SCC; its effect could sustain 24 weeks after treatment stopped.

Effect of Anterograde Lavage via Temporary Loop Ileostoma on the Recovery of Bowel Function in Patients Receiving Stoma Closure: A Retrospective Cohort Study

BACKGROUND

The effect of anterograde lavage in patients with rectal cancer who underwent anterior resection and plan to receive stoma closure is unclear.

OBJECTIVE

This study aimed to investigate the effect of anterograde lavage on postoperative bowel function recovery in patients who underwent temporary loop ileostomy and stoma closure.

DESIGN

This was a hospital-based retrospective cohort study.

SETTINGS

This study was conducted at a tertiary referral center.

PATIENTS

All consecutive patients who underwent anterior resection for rectal cancer and were planning to receive stoma closure from March through December 2019 were included.

INTERVENTIONS

The enrolled patients were divided into 2 groups according to whether they received anterograde lavage before stoma closure.

MAIN OUTCOME MEASURES

Short-term functional outcomes, including time to first passing of flatus, first defecation time, and recovery time to first meal, were compared between the groups. Secondary outcomes included length of hospital stay, total cost of hospitalization, and postoperative complications.

RESULTS

A total of 222 eligible participants were included in the analysis, including 114 in the lavage group and 108 in the nonlavage group. No statistically significant differences were found in age, sex ratio, or distance between the anastomotic line and dentate line. In the lavage group, patients' time to first passing of flatus (38 vs 42 h; p = 0.006), first defecation time (42 vs 48 h; p < 0.001), recovery time to first meal (48 vs 55.5 h; p < 0.001), and length of hospital stay (5 vs 7 d; p < 0.001) were significantly shorter than those in the nonlavage group, and the total cost of hospitalization was significantly lower than that of the nonlavage group (25,000 vs 28,000 RMB; p < 0.001). No significant difference was found in the incidence of postoperative complications between the 2 groups (p = 0.067).

LIMITATIONS

This study is limited by its relatively small sample size and retrospective design with single-center participants.

CONCLUSIONS

Anterograde lavage before stoma closure is safe and noninvasive. For patients receiving anterior resection and planning to have stoma closure, this procedure can potentially help recover bowel function more rapidly. See Video Abstract at http://links.lww.com/DCR/C51.

EFECTO DEL LAVADO ANTERGRADO MEDIANTE ILEOSTOMA TEMPORAL EN ASA SOBRE LA RECUPERACIN DE LA FUNCIN INTESTINAL EN PACIENTES QUE RECIBEN CIERRE DE ESTOMA UN ESTUDIO DE COHORTE RETROSPECTIVO

ANTECEDENTES:No está claro el efecto del lavado anterógrado en pacientes con cáncer de recto con resección anterior que planean recibir el cierre del estoma.OBJETIVO:Investigar el efecto del lavado anterógrado en la recuperación de la función intestinal posoperatoria en pacientes que se sometieron a ileostomía en asa temporal y cierre de estoma.DISEÑO:Estudio de cohorte retrospectivo basado en el hospital.AJUSTES:Centro de referencia terciario.PACIENTES:Todos los pacientes que se sometieron a una resección anterior por cáncer de recto y que planeaban recibir el cierre del estoma desde marzo hasta diciembre de 2019.INTERVENCIONES:Los pacientes inscritos se dividieron en dos grupos según si recibieron lavado anterógrado antes del cierre del estoma.PRINCIPALES MEDIDAS DE RESULTADO:Los resultados funcionales a corto plazo, incluido el tiempo de la primera evacuación de flatos, tiempo de la primera defecación y tiempo de recuperación hasta la primera comida, se compararon entre los grupos. Resultados secundarios incluyeron duración de la estancia hospitalaria, costo total de la hospitalización y complicaciones posoperatorias.RESULTADOS:Se incluyeron en el análisis un total de 222 participantes elegibles, incluidos 114 en el grupo de lavado y 108 en el grupo de no lavado. No hubo diferencias estadísticamente significativas en la edad, la proporción de sexos o la distancia entre la línea de anastomosis y la línea dentada. En el grupo de lavado, el tiempo de la primera evacuación de flatos de los pacientes (38 vs 42 h; p = 0,006), el tiempo de la primera defecación (42 vs 48 h; p < 0,001), el tiempo de recuperación hasta la primera comida (48 vs 55,5 h; p < 0,001) y la duración de la estancia hospitalaria (5 vs 7 días; p < 0,001) fueron significativamente más cortos que los del grupo de no lavado, y el costo total de la hospitalización fue significativamente menor que el del grupo de no lavado (25000 vs 28000 RMB; p < 0,001). No hubo diferencia significativa en la incidencia de complicaciones postoperatorias entre los dos grupos (p = 0,067).LIMITACIONES:Este estudio está limitado por su tamaño de muestra relativamente pequeño y su diseño retrospectivo con participantes de un solo centro.CONCLUSIONES:El lavado anterógrado antes del cierre del estoma es seguro y no invasivo. Para los pacientes que se someten a una resección anterior y planean cerrar el estoma, este procedimiento puede ayudar potencialmente a recuperar la función intestinal más rápidamente. Consulte Video Resumen en http://links.lww.com/DCR/C51. (Traducción-Dr. Francisco M. Abarca-Rendon).

The role of neuromodulation in chronic functional constipation: a systematic review

BACKGROUND

Chronic functional constipation is a highly prevalent disorder in which, when conservative measures fail to relieve symptoms, surgical interventions are sometimes indicated. In recent years, neuromodulation for the treatment of functional constipation has gained interest but its role and effectiveness are still unclear. The purpose of this review is to provide a systematic overview on the current literature on the different modalities of neurostimulation and their effect on chronic functional constipation in adults as reported in the literature.

METHODS

A search in the literature for articles concerning the effect of different types of neuromodulation on constipation was performed in PubMed using extensive search terms for the different modalities of neuromodulation. Studies and trials were checked for eligibility. For all types of neuromodulation together, 27 articles were included.

RESULTS

17 studies were included on SNM (sacral nerve modulation). Although multiple studies show positive results on the effect of SNM in constipation, double-blind crossover RCT's (randomised controlled trials) showed no significant effect. 3 studies were included for tSNS (transcutaneous sacral nerve stimulation), 2 for PTNS (percutaneous tibial nerve stimulation) and 2 for TTNS (transcutaneous tibial nerve stimulation). Studies and trials on these modalities of neuromodulation reported ambiguous results on statistical significance of the effect. For transcutaneous IFC (interferential current therapy) 2 studies were included, which both reported a statistically significant effect on all outcomes.

CONCLUSION

The beneficial effect of neuromodulation in chronic functional constipation remains questionable. However, neuro-modulation might be worth considering in patients refractory to treatment before turning to more invasive measures. Future research should shed more light on the effects of neuromodulation in constipation.

Effectiveness of different acupuncture courses for functional constipation: A protocol for systematic review and network meta-analysis

BACKGROUND

This study will evaluate the effectiveness of different acupuncture courses for functional constipation (FC) through network meta-analysis.

METHODS

Eight database (PubMed, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials (Central), China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM) and Wanfang Database) will be searched from inception to October 2019. Only randomized controlled trials comparing different acupuncture courses or acupuncture versus sham acupuncture or placebo will be included. The outcomes involved weekly stool frequency, Bristol Fecal score, responder rate and safety evaluation. The risk of bias assessment and quality of evidence will be appraised using the Cochrane Risk of Bias Tool and the Grading of Recommendations, Assessment, Development and Evaluation guidelines. RevMan 5.3 software, STATA V.14.0 and GeMTC software will be used to perform the network meta-analysis.

RESULTS

This work will compare and arrange the comparative efficacy of different acupuncture treatments for FC by summarizing the current evidences. The results will be submitted in the form of a journal publication.

CONCLUSION

The results of this network meta-analysis may help doctors determine the best treatments for patients to manage FC.

PROSPERO REGISTRATION NUMBER

CRD42020153801.

Subtotal colectomy and ileorectal anastomosis for slow transit constipation: clinical follow-up at median of 15 years

BACKGROUND

Slow transit constipation is characterised by prolonged colonic transit and reliance on laxatives. The pathophysiology is poorly understood and in its most severe form, total colectomy with ileorectal anastomosis is the final treatment option. We present a follow-up study of the long-term function in patients who had surgery for laxative-resistant slow transit constipation.

METHODS

A postal survey was sent to assess bowel frequency, abdominal pain, St Mark's continence score, satisfaction with procedure, likelihood to choose the procedure again, and long-term rates of small bowel obstruction and ileostomy. Longitudinal data from a subgroup studied 23 years previously are reported.

RESULTS

Forty-two patients (male = 2) were available for follow-up out of an initial cohort of 102. Mean time since surgery was 15.9 years (range 1.7-29.7) years. Fifty percent had < 4 bowel motions per day, most commonly Bristol stool 6, mean St Mark's score 7.45. Twenty-one percent had severe incontinence. Satisfaction and likelihood to choose surgery were high (median 10/10). There was a high rate of small bowel obstruction, suggesting pan-intestinal dysmotility in some cases. Conversion to ileostomy occurred in 8 patients. In the longitudinal follow-up in 15 subjects, continence deteriorated (p < 0.01), stool consistency softened (p < 0.01), and stool frequency fell (p < 0.01).

CONCLUSIONS

Satisfactory stool frequency was achieved in the long term, and although 21% had incontinence scores > 12, patient satisfaction was high. This is the longest reported follow-up of colectomy for slow transit constipation, with longitudinal outcomes reported. There was considerable attrition of patients, so larger, longitudinal studies are required to better ascertain the functional outcomes of these patients.

The effect and safety of acupuncture on patients with functional constipation: Protocol for a systematic review and meta-analysis of high quality RCTs

BACKGROUND

Functional constipation (FC) is a prevalent clinical disease that affects a considerable proportion of the population of all ages. Persistent FC significantly reduces quality of life and influences physical and emotional well-being, as well as consumes many substantial healthcare resources. Acupuncture originates from Traditional Chinese Medicine (TCM), and emerging evidence of several randomized controlled trials (RCTs) published suggest that acupuncture has positive effects for FC. Since 2019, several new results of high quality RCTs about acupuncture treatment for FC have been published. Thus a systematic review will be designed to appraise the effectiveness and safety of acupuncture for improvement of FC in patients based on high quality RCTs.

METHODS

We carried out a rigorous literature search in English and Chinese electronic database from inception to present. Two reviewers will identify relevant studies, extract and manage trial information, and then assess the risk of bias in included studies by the Cochrane risk of bias assessment tool. Only high quality RCTs will be included. Data will be synthesized by either fixed-effects or random-effects model regarding to a heterogeneity test. The primary outcome measurement will be the change from baseline in mean complete spontaneous bowel movements and stool form. The secondary outcomes involved disappearance rate of symptoms, proportion of responders, mean transit time, health-related quality of life, and safety of intervention. Meta-analysis will be performed by using Cochrane's RevMan software.

RESULTS

This systematic review will summarize high quality clinical evidence to assess and appraise the effectiveness and safety of acupuncture treatment for FC patient.

EXPECTED CONCLUSION

This systematic review and meta-analysis will provide evidence to determine whether acupuncture treatment is an effective and safe therapy for the prevention and treatment of FC compared with medication treatment.

Incidence of opioid-induced constipation in Japanese patients with cancer pain: A prospective observational cohort study

This multicenter, prospective, observational cohort study assessed opioid induced constipation (OIC) in Japanese patients with cancer. Eligible patients had stable cancer and an ECOG PS of 0-2. OIC incidence based on the Rome IV diagnostic criteria was determined by patient diary entries during the first 14 days of opioid therapy. The proportion of patients with OIC was calculated for each 1-week period and the overall 2-week study period. Secondary measurements of OIC included the Bowel Function Index (BFI) score (patient assessment administered by physician), spontaneous bowel movements (SBMs) per week (patient assessment), and physician assessments. Medication for constipation was allowed. Two hundred and twenty patients were enrolled. The mean morphine-equivalent dose was 22 mg/day. By Rome IV criteria, the cumulative incidence of OIC was 56% (95% CI: 49.2%-62.9%); week 1, 48% (95% CI: 40.8%-54.6%); week 2, 37% (95% CI: 30.1%-43.9%). The cumulative incidence of OIC was lower in patients who received prophylactic agents for constipation (48% [95% CI: 38.1%-57.5%]) than in patients who did not (65% [95% CI: 55.0%-74.2%]). The cumulative incidences of OIC were 59% (95% CI: 51.9%-66.0%), 61% (95% CI: 54.3%-68.1%), and 45% (95% CI: 38.0%-51.8%) based on BFI scores, physician assessments, and SBM frequency, respectively. Frequency of BMs/week before starting opioids was the most influential factor for the occurrence of OIC. Utilization of prophylactic agents for constipation was associated with a modest effect on reducing the incidence of OIC. The incidences of OIC reported were variable depending on the diagnostic tool involved.

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.

Percutaneous endoscopic colostomy for adults with chronic constipation: Retrospective case series of 12 patients

BACKGROUND

Percutaneous endoscopic colostomy (PEC) is a technique derived from percutaneous endoscopic gastrostomy. When conservative treatment of chronic obstipation fails, colon irrigation via PEC seems less invasive than surgical interventions. However, previous studies have noted high complication rates of PEC, mostly related to infections. Our aim was to report our experiences with PEC in patients with chronic refractory constipation.

METHODS

Retrospective analysis of all patients who underwent PEC for refractory constipation in our secondary referral hospital between 2009 and 2016.

KEY RESULTS

Twelve patients received a PEC for chronic, refractory constipation. Short-term efficacy for relief of constipation symptoms was good in 8 patients and moderate in 4 patients. Two patients had the PEC removed because of spontaneous improvement of constipation. Three patients, who initially noticed a positive effect, preferred an ileostomy over PEC after 1-5 years. One PEC was removed because of an abscess. Long-term efficacy is 50%: 6 patients still use their PEC after 3.3 years of follow-up. No mortality occurred.

CONCLUSIONS AND INTERFERENCES

PEC offers a technically easily feasible and safe treatment option for patients with chronic constipation not responding to conventional therapy. Long-term efficacy of PEC in our patients is 50%.

Naringenin induces laxative effects by upregulating the expression levels of c-Kit and SCF, as well as those of aquaporin 3 in mice with loperamide-induced constipation

Constipation is a common affliction which causes discomfort and affects the quality of life of affected individuals. Naringenin (NAR), a natural flavonoid widely found in citrus fruits and tomatoes, has been reported to exhibit various pharmacological effects, such as anti-inflammatory, anti-atherogenic, anti-mutagenic, hepatoprotective and anticancer effects. Increasing evidence has indicated that NAR has potential for use in the treatment of constipation. Thus, the aim of this study was to evaluate the laxative effects of NAR in mice with loperamide-induced (Lop-induced) constipation. The data indicated that NAR relieved Lop-induced constipation in mice based on the changes of fecal parameters (numbers, weight and water content), the intestinal charcoal transit ratio and the histological alteration. ELISA revealed that NAR regulated the production levels of gastrointestinal metabolic components, such as motilin (MTL), gastrin (Gas), endothelin (ET), substance P (SP), acetylcholinesterase (AChE) and vasoactive intestinal peptide (VIP) in serum. The expression levels of enteric nerve-related factors, glial cell line-derived neurotrophic factor (GDNF), transient receptor potential vanilloid 1 (TRPV1), nitric oxide synthase (NOS), c-Kit, stem cell factor (SCF) and aquaporin 3 (AQP3) were examined by western blot analysis and RT-PCR analysis. The results of this study suggest that NAR relieves Lop-induced constipation by increasing the levels of interstitial cells of Cajal markers (c-Kit and SCF), as well as AQP3. Thus, NAR may be effective as a candidate in patients suffering from lifestyle-induced constipation.

Luminally Acting Agents for Constipation Treatment: A Review Based on Literatures and Patents

Constipation is one of the most frequently reported gastrointestinal (GI) disorders that negatively impacts quality of life and is associated with a significant economic burden to the patients and society. Traditional treatments including lifestyle modification and laxatives are often ineffective in the more severe forms of constipation and over the long term. New medications targeting at intestinal chloride channels and colonic serotonin receptors have been demonstrated effective in recent years. Emerging agents focusing on improving intestinal secretion and/or colonic motility have been shown effective in animal models and even in clinical trials. Recognization of the role of cystic fibrosis transmembrane regulator (CFTR) and calcium-activated chloride channels (CaCCs) in intestine fluid secretion and motility modulation makes CFTR and CaCCs promising molecule targets for anti-constipation therapy. Although there are multiple choices for constipation treatment, there is still a recognized need for new medications in anti-constipation therapy. The present review covers the discovery of luminally acting agents for constipation treatment described in both patents (2011–present) and scientific literatures.

Clinical application of a gadolinium-based capsule as an MRI contrast agent in slow transit constipation diagnostics

BACKGROUND

As a traditional method for the assessment of colon dynamics, radio-opaque markers (ROMs) are limited in clinical use because of their ionizing radiation. We compared the accuracy and applicability of gadolinium-based capsules with ROMs in the measurement of colon dynamics in healthy controls and slow transit constipation (STC) patients.

METHODS

Seven patients with STC and nine healthy controls under a normal diet orally consumed ROMs and gadolinium-based capsules simultaneously. All subjects underwent X-ray and magnetic resonance imaging (MRI). Healthy control images were acquired at 12, 24, and 48 h, and STC patient images were acquired at 24, 48, and 72 h. The scores based on the position of the labeling capsules and ROMs in the colon and the colon transit times (CTTs) in the two groups were compared.

KEY RESULTS

The CTTs obtained via the ROMs were 34.7±17.4 and 67.3±6.5 h in the healthy controls and STC patients, respectively (P<.05). The CTTs obtained via MRI were 30.9±15.9 and 74.1±7.2 h in the healthy controls and STC patients, respectively (P<.05). The CTTs of the STC patients were significantly longer than the healthy controls. The correlation (r_s ) between the scores based on the position of the labeling capsule and ROMs in the healthy group and the STC patients was .880 (P<.05) and .889 (P<.05), respectively.

CONCLUSIONS AND INFERENCES

As a MRI contrast label, gadolinium-based capsules exhibit results comparable to ROMs in colon motility measurements.

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.

Sacral Nerve Stimulation Fails to Offer Long-term Benefit in Patients With Slow-Transit Constipation

BACKGROUND

Sacral nerve stimulation is proposed as a treatment for slow-transit constipation. However, in our randomized controlled trial we found no therapeutic benefit over sham stimulation. These patients have now been followed-up over a long-term period.

OBJECTIVE

The purpose of this study was to assess the long-term efficacy of sacral nerve stimulation in patients with scintigraphically confirmed slow-transit constipation.

DESIGN

This study was designed for long-term follow-up of patients after completion of a randomized controlled trial.

SETTINGS

It was conducted at an academic tertiary public hospital in Sydney.

PATIENTS

Adults with slow-transit constipation were included.

MAIN OUTCOME MEASURES

At the 1- and 2-year postrandomized controlled trial, the primary treatment outcome measure was the proportion of patients who reported a feeling of complete evacuation on >2 days per week for ≥2 of 3 weeks during stool diary assessment. Secondary outcome was demonstration of improved colonic transit at 1 year.

RESULTS

Fifty-three patients entered long-term follow-up, and 1 patient died. Patient dissatisfaction or serious adverse events resulted in 44 patients withdrawing from the study because of treatment failure by the end of the second year. At 1 and 2 years, 10 (OR = 18.8% (95% CI, 8.3% to 29.3%)) and 3 patients (OR = 5.7% (95% CI, -0.5% to 11.9%)) met the primary outcome measure. Colonic isotope retention at 72 hours did not differ between baseline (OR = 75.6% (95% CI, 65.7%-85.6%)) and 1-year follow-up (OR = 61.7% (95% CI, 47.8%-75.6%)).

LIMITATIONS

This study only assessed patients with slow-transit constipation.

CONCLUSIONS

In these patients with slow-transit constipation, sacral nerve stimulation was not an effective treatment.

Chronic Constipation: a Review of Current Literature

Chronic constipation is a common health condition representing a substantial proportion of primary care visits and referrals to specialist providers. Chronic constipation can have a significant negative effect on health-related quality of life and has been associated with psychological distress in severely affected patients. It has the potential to cause patients to curtail work, school, and social activities. While different pathophysiological mechanisms have been implicated in the development of chronic constipation, in some instances, the causes of chronic constipation are not easily determined. Expenditures for the evaluation and management of chronic constipation represent a significant burden on patients and payers, and it is important for clinicians to have a clear understanding of the different pathophysiological mechanisms associated with constipation, understand the different testing modalities and treatments that are available including their appropriateness and limitations, and tailor that knowledge to the management of individual patients.