Normal aspects of colorectal motility and abnormalities in slow transit constipation

Examining linaclotide for the treatment of chronic idiopathic constipation

INTRODUCTION

Chronic idiopathic constipation (CIC) is characterized by infrequent bowel movements and hard stools lasting for at least three months or longer. This disease affects 8-12% of the US population and 10-17% of the world population. Treatment and management involve identifying the primary cause, changing dietary habits, and adequate physical activity. Linaclotide is a guanylate cyclase-agonist acting locally in the luminal surface of the intestinal enterocyte leading to a signal transduction cascade, activation of the cystic fibrosis transmembrane conductance regulator (CFTR), thus increasing secretion of chloride and bicarbonate into the intestinal lumen with eventual increased intestinal fluid and faster transit time.

AREAS COVERED

We reviewed multiple studies and did a thorough literature review on CIC including its pathophysiology. Through this literature review, we were able to discuss and give the context and rationale for drug regimens indicated for CIC.

EXPERT OPINION

The era we live in right now is akin to nutrient-rich and fertilized soil as knowledge and resources are abundant. The opportunities and potential are endless. Constipation being more extensively studied, our understanding of medications and diseases broadens, leading to novel medications being discovered. Linaclotide is a pioneer in this aspect and can pave the way for future generations.

Management of the child with refractory constipation

BACKGROUND

Caring for children with constipation refractory to conventional treatment can be challenging and management practices vary widely.

AIMS

To review recent advances in the evaluation and treatment of children with refractory constipation and to propose an algorithm that incorporates the latest evidence and our institutional experience.

METHODS

We performed a literature review on diagnostic tests and treatment options for children with refractory constipation.

RESULTS

Evaluation of a child with refractory constipation seeks to better understand factors contributing to an individual child's presentation. Anorectal manometry evaluating for a rectal evacuation disorder and colonic manometry evaluating for colonic dysmotility can guide subsequent treatment. For the child who has not responded to conventional treatment, a trial of newer medications like linaclotide can be helpful. Transanal irrigation offers a safe and effective alternative for families able to administer daily rectal treatment. Despite mixed evidence in children, pelvic floor biofeedback therapy can help some children with pelvic floor dyssynergia. For younger children unable to cooperate with pelvic floor therapy, or older children with refractory symptoms, internal anal sphincter botulinum toxin injection can be beneficial. Antegrade continence enema treatment can be effective for children with either normal colonic motility or segmental dysmotility. Sacral nerve stimulation is generally reserved for symptoms that persist despite antegrade continence enemas, particularly if faecal incontinence is prominent. In more severe cases, temporary or permanent colonic diversion and segmental colonic resection may be needed.

CONCLUSIONS

Recent advances offer hope for children with refractory constipation.

Position paper on transanal irrigation in chronic non-organic constipation

The practice of recto-colonic water irrigation to treat constipation has been used since ancient times with different, uncontrolled, and variably performing methods which have been considered interchangeably all alike. The use of better-performing devices with a standardized methodology is relatively recent, and the term Trans Anal Irrigation (TAI) defines a methodology performed with devices able to control the timing, volume, and pressure of the water introduced into the rectum and colon utilizing a catheter or a cone through the anus. Such practice has been implemented with favorable responses in patients with refractory chronic constipation secondary to neurological diseases. However, since the role of Trans Anal Irrigation as a therapeutic aid in chronic functional constipation and functional evacuation disorders is not yet fully clarified and standardized, a group of clinical investigators with recognized expertise in these clinical conditions intends to clarify the elements that characterize a TAI procedure that can benefit patients with functional constipation and functional defecation disorders defined according to the lastly updated Rome Diagnostic Criteria. Finally, the paper deals with adherence and practical implementation of TAI.

Superior Rectal Artery Preservation in Laparoscopically Assisted Subtotal Colectomy and Ileorectal Anastomosis for Slow-Transit Constipation

Our previous retrospective observational study demonstrated the safety of laparoscopically assisted subtotal colectomy with ileorectal anastomosis and preservation of the superior rectal artery (SRA), without instances of leakage, in patients with slow-transit constipation (STC). Thus, we extended the enrollment period and enlarged the sample size to detect the differences in the postoperative complications and surgical and functional outcomes between patients who underwent laparoscopically assisted subtotal colectomy with and without SRA preservation. We conducted a retrospective single-center analysis of patients with STC who underwent laparoscopically assisted subtotal colectomy between 2016 and 2020. The diagnosis of STC was based on the colonic transit and anal functional tests and barium enema to exclude secondary causes. Patients were divided into group A, which underwent surgery with SRA preservation, and group B, which underwent ligation of the SRA during surgery. Outcome assessments for both groups included the incidence of anastomotic breakdown, intraoperative complications, length of hospital stay, estimated blood loss, time to first flatus, and complications. Propensity score matching allocated 34 patients to groups A and B each. Postoperative bowel function, including time to first flatus, stool, and oral intake, recovered better in group A than in group B. Anastomotic leakage, a significant postoperative complication, was less frequent in patients with SRA preservation. In conclusion, preservation of the SRA in patients undergoing laparoscopically assisted subtotal colectomy with ileorectal anastomosis for STC is associated with favorable postoperative bowel function recovery and lower anastomotic leakage rates.

Relief from behind: enemas, the back door enforcement to help treating chronic constipation in adults

INTRODUCTION

Chronic constipation is a frequent symptom encountered in the daily clinical practice. The treatment of this condition mainly relies on the use of laxatives. However, patients' satisfaction with this approach is limited, and alternative measures are often added to the treatment. Among these, particularly frequent worldwide is the use of enemas, even though literature data on its scientific validity are scarce.

AREAS COVERED

In this article, by an extensive online search of Medline (through PubMed), Scopus, Cochrane CENTRAL, EMBASE, and the Science Citation Index, the available literature data on the use of enemas in adult patients with chronic constipation, also in the perspective of available guidelines on treatment of this pathological condition, were analyzed.

EXPERT OPINION

Although the use of enemas remains a frequently employed method and it is considered as useful by many physicians as an adjunctive support for the treatment of chronic constipation in adults, this practice is not substantiated by rigorous scientific data, and some studies are available only for specific instances (fecal impaction, transanal irrigation). Thus, waiting for more robust scientific data, enemas treatment should be carried out on an individual patient's basis, according to the experience of the caring physicians.

Transdermal Administration of Volatile Oil from Citrus aurantium-Rhizoma Atractylodis Macrocephalae Alleviates Constipation in Rats by Altering Host Metabolome and Intestinal Microbiota Composition

Background

The Citrus aurantium- (ZhiShi, ZS-) Rhizoma Atractylodis Macrocephalae (BaiZhu, BZ) pairs are often found in herbal formulas for constipation. The volatile oils of ZS and BZ (ZBVO) have good pharmacological activity against constipation, but the mechanism for treatment of slow transit constipation (STC) remains unclear.

Method

A rat model using diphenoxylate tablets was constructed to investigate if transdermal administration of ZBVO would mediate intestinal microorganisms and fecal metabolites and improve STC symptoms. The regulatory effects of ZBVO at 0.15, 0.30, and 0.60 mL kg⁻¹ d⁻¹ on STC rats were assessed by measuring fecal water content, intestinal propulsion rate, histopathology, expression of gastrointestinal hormones, brain and intestinal peptides, and inflammatory factors. The changes in intestinal flora of STC rats were analyzed by 16S rRNA gene sequencing. Moreover, the untargeted fecal metabolomics analysis was performed by ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometer (UPLC-Q-TOF-MS) technology.

Results

The results showed that ZBVO had a modulating effect on STC by increasing the fecal water content and intestinal propulsion rate. Transdermal administration of ZBVO decreased serum levels of interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) and increased the levels of gastrin (GAS) and substance P (SP). In addition, ZBVO increased 5-hydroxytryptamine (5-HT) levels and decreased vasoactive intestinal peptide (VIP) levels in colon and hippocampus tissues. The results of intestinal microbiota showed that ZBVO improved the diversity and abundance of intestinal microbiota and changed the community composition by decreasing Romboutsia and increasing Proteobacteria, Allobaculum, and Ruminococcaceae. And the feces metabolomics found that nicotinate and nicotinamide metabolism, purine metabolism, citrate cycle (TCA cycle), pyruvate metabolism, arachidonic acid metabolism, pyrimidine metabolism, and primary bile acid biosynthesis were modulated.

Conclusion

These findings suggest that ZBVO can alleviate STC symptoms by promoting intestinal peristalsis, increasing fecal water content, regulating gastrointestinal hormone level, reducing the inflammatory response, and regulating brain and intestinal peptides after transdermal administration. And structural changes in the intestinal microbiota are closely related to host metabolism and intestinal microbiota destroyed in STC modeling could be significantly improved by the ZBVO, which provides a reference for the development of aromatic drug macrohealth products.

Magnetically-propelled fecal surrogates for modeling the impact of solid-induced shear forces on primary colonic epithelial cells

The colonic epithelium is continuously exposed to an array of biological and mechanical stimuli as its luminal contents are guided over the epithelial surface through regulated smooth muscle contraction. In this report, the propulsion of solid fecal contents over the colonic epithelium is recapitulated through noninvasive actuation of magnetic agarose hydrogels over primary intestinal epithelial cultures, in contrast to the vast majority of platforms that apply shear forces through liquid microflow. Software-controlled magnetic stepper motors enable experimental control over the frequency and velocity of these events to match in vivo propulsive contractions, while the integration of standardized well plate spacing facilitates rapid integration into existing assay pipelines. The application of these solid-induced shear forces did not deleteriously affect cell monolayer surface coverage, viability, or transepithelial electrical resistance unless the device parameters were raised to a 50× greater contraction frequency and 4× greater fecal velocity than those observed in healthy humans. At a frequency and velocity that is consistent with average human colonic motility, differentiation of the epithelial cells into absorptive and goblet cell phenotypes was not affected. Protein secretion was modulated with a two-fold increase in luminal mucin-2 secretion and a significant reduction in basal interleukin-8 secretion. F-actin, zonula occludens-1, and E-cadherin were each present in their proper basolateral locations, similar to those of static control cultures. While cellular height was unaffected by magnetic agarose propulsion, several alterations in lateral morphology were observed including decreased circularity and compactness, and an increase in major axis length, which align with surface epithelial cell morphologies observed in vivo and may represent early markers of luminal exfoliation. This platform will be of widespread utility for the investigation of fecal propulsive forces on intestinal physiology, shedding light on how the colonic epithelium responds to mechanical cues.

Preservation of superior rectal artery in laparoscopically assisted subtotal colectomy with ileorectal anastomosis for slow transit constipation

BACKGROUND

Slow transit constipation (STC) has traditionally been considered as a functional disorder. However, evidence is accumulating that suggests that most of the motility alterations in STC might be of a neuropathic etiology. If the patient does not meet the diagnosis of pelvic outlet obstruction and poorly response to conservative treatment, surgical intervention with subtotal colectomy may be effective. The most unwanted complication of the procedure is anastomotic leakage, however, preservation of the superior rectal artery (SRA) may reduce its incidence.

AIM

To evaluate the preservation of the SRA in laparoscopically assisted subtotal colectomy with ileorectal anastomosis in STC patients.

METHODS

This was a single-center retrospective observational study. STC was diagnosed after a series of examinations which included a colonic transit test, anal manometry, a balloon expulsion test, and a barium enema. Eligible patients underwent laparoscopically assisted total colectomy with ileorectal anastomosis and were examined between January 2016 and January 2018. The operation time, blood loss, time to first flatus, length of hospital days, and incidence of minor or major complications were recorded.

RESULTS

A total of 32 patients (mean age, 42.6 years) who had received laparoscopic assisted subtotal colectomy with ileorectal artery anastomosis and preservation of the SRA. All patients were diagnosed with STC after a series of examinations. The mean operative time was 151 min and the mean blood loss was 119 mL. The mean day of first time to flatus was 3.0 d, and the mean hospital stay was 10.6 d. There were no any patients conversions to laparotomy. Post-operative minor complications including 1 wound infection and 1 case of ileus. There was no surgical mortality. No anastomosis leakage was noted in any of the patients.

CONCLUSION

Laparoscopically assisted subtotal colectomy with ileorectal anastomosis and preservation of the SRA can significantly improve bowel function with careful patient selection. Sparing the SRA may protect against anastomosis leakage.

Simultaneous assessment of colon motility in children with functional constipation by cine-MRI and colonic manometry: a feasibility study

BACKGROUND

Colonic manometry is the current reference standard for assessing colonic neuromuscular function in children with intractable functional constipation (FC). Recently, cine magnetic resonance imaging (cine-MRI) has been proposed as a non-invasive alternative. We compared colonic motility patterns on cine-MRI with those obtained by manometry in children, by stimulating high-amplitude propagating contractions (HAPCs) with bisacodyl under manometric control while simultaneously acquiring cine-MRI.

METHODS

After Institutional Review Board approval, adolescents with FC scheduled to undergo colonic manometry were included. A water-perfused 8-lumen catheter was used for colonic manometry recordings. After an intraluminal bisacodyl infusion, cine-MRI sequences of the descending colon were acquired for about 30 min simultaneously with colonic manometry. Manometry recordings were analysed for HAPCs. MRI images were processed with spatiotemporal motility MRI techniques. The anonymised motility results of both techniques were visually compared for the identification of HAPCs in the descending colon.

RESULTS

Data regarding six patients (three males) were analysed (median age 14 years, range 12-17). After bisacodyl infusion, three patients showed a total of eleven HAPCs with colonic manometry. Corresponding cine-MRI recorded high colonic activity during two of these HAPCs, minimal activity during seven HAPCs, while two HAPCs were not recorded. In two of three patients with absent HAPCs on manometry, colonic activity was recorded with cine-MRI.

CONCLUSIONS

Simultaneous acquisition of colonic cine-MRI and manometry in children with FC is feasible. Their motility results did not completely overlap in the identification of HAPCs. Research is needed to unravel the role of cine-MRI in this setting.

Constipation in ulcerative colitis: pathophysiology and practical management

Clinical experience suggests that there is a cohort of patients with refractory colitis who do have faecal stasis that contributes to symptoms. The underlying physiology is poorly understood, partly because until recently the technology to examine segmental colonic motility has not existed. Patients are given little information on how proximal faecal stasis can complicate colitis. Treatment guidelines are scanty and many patients are offered little apart from laxatives and advice on increasing fibre intake, which often makes symptoms worse. This article aims to review the history, pathology and management, and create impetus for future research on this underappreciated condition.

Understanding gastrointestinal motility studies in pediatrics

Motility of the gut is affected by the nervous system, the endocrine system, smooth muscle cells, interstitial cells of Cajal, secretory mucosal cells, the immune system, and gut flora. Abnormal gastrointestinal motility can generate nonspecific symptom complaints that are refractory to standard treatment approaches. It is important to exclude anatomical obstruction or other causes for patients' symptoms prior to proceeding with motility evaluation. Motility studies that help to evaluate children with suspected motility problems include combined multichannel intraluminal impedance (MII) and pH recording, esophageal manometry, gastric emptying scinitigraphy, antroduodenal manometry, colonic manometry, and anorectal manometry. Many pediatric gastrointestinal motility evaluations should be completed in a pediatric motility center where specialized training is completed by physicians in this field. Indications for pediatric gastrointestinal motility studies and how the procedures are performed are addressed in this paper.

Optimising functional outcomes in rectal cancer surgery

Background

By improved surgical technique such as total mesorectal excision (TME), multimodal treatment and advances in imaging survival and an increased rate of sphincter preservation have been achieved in rectal cancer surgery. Minimal-invasive approaches such as laparoscopic, robotic and transanal-TME (ta-TME) enhance recovery after surgery. Nevertheless, disorders of bowel, anorectal and urogenital function are still common and need attention.

Purpose

This review aims at exploring the causes of dysfunction after anterior resection (AR) and the accordingly preventive strategies. Furthermore, the indication for low AR in the light of functional outcome is discussed. The last therapeutic strategies to deal with bowel, anorectal, and urogenital disorders are depicted.

Conclusion

Functional disorders after rectal cancer surgery are frequent and underestimated. More evidence is needed to define an indication for non-operative management or local excision as alternatives to AR. The decision for restorative resection should be made in consideration of the relevant risk factors for dysfunction. In the case of restoration, a side-to-end anastomosis should be the preferred anastomotic technique. Further high-evidence clinical studies are required to clarify the benefit of intraoperative neuromonitoring. While the function of ta-TME seems not to be superior to laparoscopy, case-control studies suggest the benefits of robotic TME mainly in terms of preservation of the urogenital function. Low AR syndrome is treated by stool regulation, pelvic floor therapy, and transanal irrigation. There is good evidence for sacral nerve modulation for incontinence after low AR.

Dietary Proteins Regulate Serotonin Biosynthesis and Catabolism by Specific Gut Microbes

More than 90% of serotonin is produced in the intestine. Previous studies have shown that different protein diets significantly affect serum serotonin levels. Here, the colonic microbiota and intestinal serotonin were measured to elaborate how protein diets affect serotonin production in a mouse model. The emulsion-type sausage protein and cooked pork protein diets increased the mRNA levels of tryptophan hydroxylase 1 (Tph1) and monoamine oxidase A (Maoa) and serotonin level as well but reduced the number of enterochromaffin cells. However, the soy protein diet increased the number of enterochromaffin cells and Tph1 mRNA level but decreased the Maoa mRNA level and the serotonin content. Specific gut microbes that responded to dietary changes and affected the content of short-chain fatty acids were significantly related to serotonin-associated biomarkers. These results suggest that dietary proteins may regulate serotonin biosynthesis and catabolism by altering specific gut microbes.

On the nature of high-amplitude propagating pressure waves in the human colon

Characterization of high-amplitude propagating pressure waves (HAPWs or HAPCs) plays a key role in diagnosis of colon dysmotility using any type of colonic manometry. With the introduction of high-resolution manometry, more insight is gained into this most prominent propulsive motor pattern. Here, we use a water-perfused catheter with 84 sensors with intervals between measuring points of 1 cm throughout the colon, for 6-8 h, in 19 healthy subjects. The catheter contained a balloon to evoke distention. We explored as stimuli a meal, balloon distention, oral prucalopride, and bisacodyl injection, with a goal to optimally evoke HAPWs. We developed a quantitative measure of HAPW activity, the "HAPW Index." Our protocol elicited 290 HAPWs. 21% of HAPWs were confined to the proximal colon with an average amplitude of 75.3 ± 3.3 mmHg and an average HAPW Index of 440 ± 58 mmHg·m·s. 29% of HAPWs started in the proximal colon and ended in the transverse or descending colon, with an average amplitude of 87.9 ± 3.1 mmHg and an average HAPW Index of 3,344 ± 356 mmHg·m·s. Forty-nine percent of HAPWs started and ended in the transverse or descending colon with an average amplitude of 109.3 ± 3.3 mmHg and an average HAPW Index of 2,071 ± 195 mmHg·m·s. HAPWs with and without simultaneous pressure waves (SPWs) initiated the colo-anal reflex, often abolishing 100% of anal sphincter pressure. Rectal bisacodyl and proximal balloon distention were the most optimal stimuli to evoke HAPWs. These measures now allow for a confident diagnosis of abnormal motility in patients with colonic motor dysfunction.NEW & NOTEWORTHY High-amplitude propagating pressure waves (HAPWs) were characterized using 84 sensors throughout the entire colon in healthy subjects, taking note of site of origin, site of termination, amplitude, and velocity, and to identify optimal stimuli to evoke HAPWs. Three categories of HAPWs were identified, including the associated colo-anal reflex. Proximal balloon distention and rectal bisacodyl were recognized as reliable stimuli for evoking HAPWs, and a HAPW Index was devised to quantify this essential colonic motor pattern.

Home-Based Transabdominal Interferential Electrical Stimulation for Six Months Improves Paediatric Slow Transit Constipation (STC)

BACKGROUND

Transcutaneous electrical stimulation (TES) for one to two months has produced some improvement in treatment-resistant slow-transit constipation (STC) in children. Optimal parameters for treatment are not known. It is possible that more improvement would occur with stimulation for longer. This study examined the effectiveness of stimulation for six months.

METHODS

Children with STC confirmed by nuclear transit study (NTS) were enrolled prospectively. All had chronic constipation for greater than two years and had failed medical treatment. TES was performed for one hour/day for six months using the INF 4160 (Fuji Dynamics) portable stimulator and 4 cm × 4 cm electrodes near the belly button and on the back. Families kept bowel diaries and completed PEDSQLCore QOL (4.0) questionnaires before and at end of treatment.

RESULTS

Sixty-two children (34 females; seven years, 2-16 year) with STC were studied. Defecation frequency increased in 57/62 (91%, mean ± SEM pre- 1.49 ± 0.20 vs. post- 3.25 ± 0.25 defecation/week, p < 0.0001) with the number with ≥3BA increasing from 6 to 37 (10-59%). Soiling frequency decreased from 4.8 to 1.1 days/week (p <0.001). Abdominal pain decreased from 1.7 to 0.3 days/week (<0.0001), and spontaneous urge to defecate improved. Quality of life (p < 0.01), mean transit index and gastric emptying on NTS improved (p < 0.005).

CONCLUSION

Treatment-resistant STC responds to TES using interferential current across the abdomen when given daily for many months. Battery operated stimulators allowed stimulation at home for an hour each day. Stimulation for six months produced clinically significant improvement in defecation frequency, soiling, abdominal pain, urge to defecate, and quality of life in half of these chronic patients.

Recording In Vivo Human Colonic Motility: What Have We Learnt Over the Past 100 Years?

To understand the abnormalities that underpin functional gut disorders we must first gain insight into the normal patterns of gut motility. While detailed information continually builds on the motor patterns (and mechanisms that control them) of the human esophagus and anorectum, our knowledge of normal and abnormal motility in the more inaccessible regions of the gut remains poor. This particularly true of the human colon. Investigation of in vivo colonic motor patterns is achieved through measures of transit (radiology, scintigraphy and, more recently, "smart pills") or by direct real-time recording of colonic contractility (intraluminal manometry). This short review will provide an overview of findings from the past and present and attempt to piece together the complex nature of colonic motor patterns. In doing so it will build a profile of human colonic motility and determine the likely mechanisms that control this motility.

An ANMS-NASPGHAN consensus document on anorectal and colonic manometry in children

BACKGROUND

Over the last few years, the study of the colon and anorectal function has experienced great technical advances that have facilitated the performance of the tests and have allowed a more detailed characterization of reflexes and motor patterns. As a result, we have achieved a much better understanding of the pathophysiology of children with defecation problems. Anorectal and colonic manometry are now commonly used in all major pediatric referral centers as diagnostic tools and to guide the management of children with intractable constipation and fecal incontinence, particularly when a surgical intervention is being considered.

PURPOSE

This review highlights some of the recent advances in pediatric colon and anorectal motility testing including indications and preparation for the studies, and how to perform and interpret the tests. This update has been endorsed by the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN).

Prucalopride succinate for the treatment of constipation: an update

Constipation is a disorder frequently complained about by patients in daily clinical practice. However, to date, its treatment is still commonly unsatisfactory, especially concerning patients' quality of life, when using conventional measures. Prucalopride, a selective 5-hydroxytryptamine receptor 4 agonist, was introduced to the market in 2009 and has been commercially available in Europe since 2010. The main effect of prucalopride is to stimulate colonic motility, which explains its efficacy to treat constipated patients unresponsive to other regimens. Literature search was carried out to look for effects of prucalopride on constipated patients. Several papers were found demonstrating that prucalopride is effective in treatment of constipated patients. Due to its few side effects, the lack of cardiovascular effects and interactions with other drugs, prucalopride may be safely used in elderly people as well.

Total Glucosides of Paeony Promote Intestinal Motility in Slow Transit Constipation Rats through Amelioration of Interstitial Cells of Cajal

Objectives

Using an atropine-diphenoxylate-induced slow transit constipation (STC) model, this study explored the effects of the total glucosides of paeony (TGP) in the treatment of STC and the possible mechanisms.

Study Design

A prospective experimental animal study.

Methods

The constipation model was set up in rats with an oral gavage of atropine-diphenoxylate and then treated with the TGP. The volume and moisture content of the faeces were observed and the intestinal kinetic power was evaluated. Meanwhile, the colorimetric method and enzyme linked immunosorbent assay (ELISA) were employed to determine the changes of nitric oxide (NO), nitric oxide synthase (NOS), vasoative intestinal peptide (VIP) and the P substance (SP) in the serum, respectively. The protein expressions of c-kit and stem cell factor (SCF) were assessed by immunohistochemical analysis and western blot, respectively, and the mRNA level of c-kit was measured by a reverse transcription polymerase chain reaction (RT-PCR).

Results

The TGP attenuated STC responses in terms of an increase in the fecal volume and moisture content, an enhancement of intestinal transit rate and the reduction of NO, NOS and VIP in the serum. In addition, the c-kit, a labeling of interstitial cells of Cajal (ICC) increased at both protein and mRNA levels. SCF, which serves as a ligand of c-kit also increased at protein level.

Conclusion

The analysis of our data indicated that the TGP could obviously attenuate STC through improving the function of ICC and blocking the inhibitory neurotransmitters such as NO, NOS and VIP.

Diagnosis and management of chronic constipation in adults

Constipation is a heterogeneous, polysymptomatic, multifactorial disease. Acute or transient constipation can be due to changes in diet, travel or stress, and secondary constipation can result from drug treatment, neurological or metabolic conditions or, rarely, colon cancer. A diagnosis of primary chronic constipation is made after exclusion of secondary causes of constipation and encompasses several overlapping subtypes. Slow-transit constipation is characterized by prolonged colonic transit in the absence of pelvic floor dysfunction. This subtype of constipation can be identified using either the radio-opaque marker test or wireless motility capsule test, and is best treated with laxatives such as polyethylene glycol or newer agents such as linaclotide or lubiprostone. If unsuccessful, subspecialist referral should be considered. Dyssynergic defecation results from impaired coordination of rectoanal and pelvic floor muscles, and causes difficulty with defecation. The condition can be identified using anorectal manometry and balloon expulsion tests and is best managed with biofeedback therapy. Opioid-induced constipation is an emerging entity, and several drugs including naloxegol, methylnaltrexone and lubiprostone are approved for its treatment. In this Review, we provide an overview of the burden and pathophysiology of chronic constipation, as well as a detailed discussion of the available diagnostic tools and treatment options.

Comparison of laparoscopic subtotal colectomy with posterior vaginal suspension and laparoscopic subtotal colectomy with transvaginal repair for patients with slow-transit constipation complicated with rectocele: a non-randomized comparative study in a single center

BACKGROUND

Slow-transit constipation complicated with rectocele is a mixed constipation difficult to treat by surgery. Different hospitals and surgeons may employ different surgical procedures. The present study aims to compare the efficacy of laparoscopic subtotal colectomy (LSC) with posterior vaginal suspension and LSC with transvaginal repair for patients having refractory slow-transit constipation complicated with rectocele.

METHODS

This paper is a retrospective study of 64 patients having refractory slow-transit constipation complicated with rectocele. Admitted from January 2002 to December 2012, the 64 patients were non-randomly divided into two groups: patients who underwent LSC with posterior vaginal suspension (Group A, 36 patients) and patients who underwent LSC with transvaginal repair (Group B, 28 patients).

RESULTS

There was no statistically significant difference (P > 0.05) in preoperative general characteristics and Wexner constipation score between Group A and Group B. There was no statistically significant difference (P > 0.05) in operative time and intraoperative blood loss between the two groups. One month after the surgery, there was no statistically significant difference (P > 0.05) in early postoperative complications, constipation recurrence rate, degree of improvement in constipation symptoms, and Wexner constipation score between the two groups. But 1-year follow-up results show that there was statistically significant difference (P < 0.05) in constipation recurrence rate, gastrointestinal quality of life index, the degree of improvement in constipation symptoms, and Wexner constipation score between the two groups.

CONCLUSION

Compared with the LSC with transvaginal repair, the LSC with posterior vaginal suspension demonstrated better efficacy in treating refractory slow-transit constipation complicated with rectocele.

Comparison of two types of colectomy in treating slow transit constipation with or without melanosis coli

AIM: To compare the follow-up outcomes of ileosigmoidal anastomosis (ISA) and caecorectal anastomosis (CRA) in patients with slow transit constipation (STC) with or without melanosis coli (MC).

METHODS: We collected the clinical data of 48 STC patients with or without MC from May 2002 to May 2007. Twenty-six patients underwent CRA (14 with MC) and 22 cases received ISA (14 with MC). A 3-year postoperative follow-up was conducted.

RESULTS: CRA improved the quality of life [evaluated by the gastrointestinal quality of life index (GIQLI)] in patients without MC, but was inferior to ISA in stool frequency and Wexner and GIQLI scores for MC patients. In the CRA group, patients with MC suffered worse outcomes than those without MC.

CONCLUSION: CRA is more suitable for STC patients without MC; however, for STC patients with MC, ISA is a better choice.

Colonic transit in the empty colon after defunctioning ileostomy: do we really know what happens?

BACKGROUND

There is disagreement amongst surgeons about the use of oral mechanical bowel preparation (MBP) prior to low anterior resection with diverting ileostomy. Colonic transit in the early post-operative period is an important factor in determining the role of MBP, as propagation of any stool remaining in the defunctioned colon may exacerbate morbidity in the event of anastomotic leak. We studied colonic transit time in the first 7 days following low anterior resection with diverting ileostomy.

METHODS

We conducted a prospective observational study of patients with rectal cancer undergoing elective low anterior resection with diverting ileostomy in a tertiary colorectal unit. Twenty radio-opaque markers were inserted into the caecum via the distal limb of the loop ileostomy at surgery. Plain abdominal radiographs were taken on post-operative days 1, 3 and 5. The primary endpoint was passage of the markers to the neorectum. Data were collected on treatment, return of gastrointestinal function and complications.

RESULTS

Twenty-two patients (mean age 68.5 years; 18 males) participated in the study. In 20 patients, all markers remained in the right colon on day 7. Three markers were present in the left colon in one patient, and eight markers were present in the neorectum in another patient, on the seventh day.

CONCLUSIONS

Colonic transit may be abolished by the presence of diverting ileostomy. It should now be established whether clearance of the left colon alone, using enemas, is sufficient for patients undergoing low anterior resection, thus avoiding the morbidity associated with oral MBP.

Intestinal manometry: who needs it?

The use of manometry, i.e. the recording of pressures within hollow viscera, after being successfully applied to the study of esophageal and anorectal motor dysfunctions, has also been used to investigate physiological and pathological conditions of the small bowel. By means of this technique, it has been possible to understand better the normal motor functions of the small intestine, and their relationship and variations following physiologic events, such as food ingestion. Moreover, intestinal manometry has proved useful to document motor abnormalities of the small bowel, although recognition of altered patterns specific for a determinate pathologic condition is still unavailable. However, this technique often permits the detection of abnormal gut motility in patients with abdominal symptoms such as unexplained vomiting and diarrhea, and it is sometimes also useful to address therapeutic targeting.

Brain-derived neurotrophic factor accelerates gut motility in slow-transit constipation

BACKGROUND & AIMS

Brain-derived neurotrophic factor (BDNF) may play a critical role in gut motility. We aimed to investigate BDNF's physiologic effects on gut motility in slow-transit constipation (STC) and to explore the underlying molecular mechanisms.

METHODS

BDNF expression and alterations of colonic nerve fibre density in STC patients were first investigated. BDNF's effects on gastrointestinal motility of both BDNF(+/-) mice and loperamide-induced constipation mice were then examined in vivo and in vitro. Smooth muscle α-actin (α-SMA) expression, and nerve fibre, neuromuscular junction (NMJ) and smooth muscle cell (SMC) alterations were investigated. Finally, the effects of BDNF-induced TrkB-phospholipase C/inositol trisphosphate (TrkB-PLC/IP3) pathway activation on gut motility were investigated.

RESULTS

In STC patients, BDNF expression and nerve fibre density were decreased, and mucosal nerve fibre ultrastructural degenerations were demonstrated. Gut motility was decreased in vivo and in vitro in BDNF(+/-) and constipation mice, with BDNF dose-dependently increasing gut motility. In BDNF(+/-) mice, α-SMA expression and nerve fibre density were decreased, and nerve fibre, NMJ and SMC ultrastructural degenerations were observed. Finally, TrkB-PLC/IP3 pathway antagonists dramatically attenuated BDNF's excitatory effect on gut motility, and exogenous BDNF induced an obvious increase in IP3 expression.

CONCLUSIONS

BDNF plays an important regulatory role in gut motility in STC. It was mediated by altering the intestinal innervation structure, as well as smooth muscle secondary degeneration through a mechanism involving TrkB-PLC/IP3 pathway activation.

Quantification of in vivo colonic motor patterns in healthy humans before and after a meal revealed by high-resolution fiber-optic manometry

BACKGROUND

Until recently, investigations of the normal patterns of motility of the healthy human colon have been limited by the resolution of in vivo recording techniques.

METHODS

We have used a new, high-resolution fiber-optic manometry system (72 sensors at 1-cm intervals) to record motor activity from colon in 10 healthy human subjects.

KEY RESULTS

In the fasted colon, on the basis of rate and extent of propagation, four types of propagating motor pattern could be identified: (i) cyclic motor patterns (at 2-6/min); (ii) short single motor patterns; (iii) long single motor patterns; and (iv) occasional retrograde, slow motor patterns. For the most part, the cyclic and short single motor patterns propagated in a retrograde direction. Following a 700 kCal meal, a fifth motor pattern appeared; high-amplitude propagating sequences (HAPS) and there was large increase in retrograde cyclic motor patterns (5.6 ± 5.4/2 h vs 34.7 + 19.8/2 h; p < 0.001). The duration and amplitude of individual pressure events were significantly correlated. Discriminant and multivariate analysis of duration, gradient, and amplitude of the pressure events that made up propagating motor patterns distinguished clearly two types of pressure events: those belonging to HAPS and those belonging to all other propagating motor patterns.

CONCLUSIONS & INFERENCES

This work provides the first comprehensive description of colonic motor patterns recorded by high-resolution manometry and demonstrates an abundance of retrograde propagating motor patterns. The propagating motor patterns appear to be generated by two independent sources, potentially indicating their neurogenic or myogenic origin.

Review of sacral neuromodulation for management of constipation

BACKGROUND

Sacral neuromodulation (SN) is an emerging treatment for constipation. This review evaluates the mechanism of action, techniques, efficacy, and adverse effects of SN in the management of constipation.

METHODS

Electronic searches for studies describing the use of SN were performed in PubMed, MEDLINE and Embase. Abstracts were reviewed and full text copies of all relevant articles obtained.

RESULTS

Fifty-nine results were obtained on the initial searches. Ten studies discussed the results of SN in patients with constipation. A total of 225 temporary neuromodulations and 125 permanent implants were performed. Bowel diaries showed improvement in assessment criteria in more than 50% of patients on temporary neuromodulation and the results were maintained in approximately 90% of patients who underwent permanent implantation over medium to long-term follow-up. The rate of adverse effects was high, but the majority of them were related to electrode position. Improvements in transit studies and anorectal physiology after neuromodulation were noted in some studies. The recognized limitations included a lack of randomized studies and an inability to perform meta-analysis.

CONCLUSION

Sacral neuromodulation may be an effective treatment in selected patients with constipation and should be a part of the management repertoire. Improvement in defecatory frequency with temporary wire placement is a good predictor of subsequent response following permanent implant. Further research into predictive factors for success would improve patient selection.

Colonic electrical stimulation for the treatment of slow-transit constipation: a preliminary pilot study

BACKGROUND

Electrical stimulation of the gastrointestinal tract is an attractive concept. In this article we report on a procedure for electrical colonic pacing due to intramuscular electrode placement for slow-transit constipation and some preliminary results.

METHODS

From January 2011 to December 2012, all consecutive patients affected by constipation and evaluated in our Pelvic Floor Center were prospectively assessed. Patients who underwent colonic electrical stimulation were evaluated for the present study.

RESULTS

In the study period, 256 patients were evaluated for constipation; 58% were identified as having obstructed defecation syndrome, 27.3% with irritable bowel syndrome or mixed forms, 4% with pelvic floor dyssynergia, and 10.5% (27 patients) as having slow-transit constipation. After failure of all the maximal conventional therapies, two patients, candidates for colectomy, agreed to undergo colonic electrical stimulation before a resective treatment. Both patients were females, aged 34 and 29 years, and were suffering from severe constipation since childhood. The follow-up was 19 and 6 months. The number of bowel movements per week increased from 0.3 to 3.5 in the first patient and from 0.5 to 2.5 in the second patient. Both patients no longer needed laxatives, enemas, or any other treatment. The hospital stay was 4 days, the mean operative time was 120 min, and no complications were reported.

CONCLUSIONS

Colonic pacing seems to be feasible and shows positive results. Further studies are required with a larger number of patients and a longer follow-up period to confirm the role of this promising treatment for slow-transit constipation.

The physiology of human defecation

Human defecation involves integrated and coordinated sensorimotor functions, orchestrated by central, spinal, peripheral (somatic and visceral), and enteric neural activities, acting on a morphologically intact gastrointestinal tract (including the final common path, the pelvic floor, and anal sphincters). The multiple factors that ultimately result in defecation are best appreciated by describing four temporally and physiologically fairly distinct phases. This article details our current understanding of normal defecation, including recent advances, but importantly identifies those areas where knowledge or consensus is still lacking. Appreciation of normal physiology is central to directed treatment of constipation and also of fecal incontinence, which are prevalent in the general population and cause significant morbidity.

Evaluating slow-transit constipation in patients using laxatives: a better approach or do we need improved patient selection?

Slow-transit constipation is a relatively frequent subtype of constipation, often refractory to medical treatment. Clinical information is usually obtained in patients during laxative withdrawal; thus, data on the effect of laxatives on their daily symptoms are lacking. The evaluated article reports on the effects of laxatives on symptoms (stool frequency, stool form, straining at stool, pain and bloating) and on laxative use by means of a daily stool questionnaire. Most patients used laxatives on an intermittent basis, and a minority also used associated enemas. Use of laxatives yielded an almost average normal daily number of evacuations in this group, with only a minority having less than three bowel movements per week. The days in which patients used laxatives yielded significantly more frequent and loose stools compared with those without laxatives. Thus, the use of laxatives seems to influence the clinical aspects of patients with slow-transit constipation, and this should be considered when evaluating these participants.

L-glutamine supplementation prevents myenteric neuron loss and has gliatrophic effects in the ileum of diabetic rats

BACKGROUND

Peripheral neuropathy caused chronically by diabetes mellitus is related to exacerbation of oxidative stress and a significant reduction in important endogenous antioxidants. L: -Glutamine is an amino acid involved in defense mechanisms and is a substrate for the formation of glutathione, the major endogenous cellular antioxidant.

AIM

This study investigated the effects of 2% L: -glutamine supplementation on peripheral diabetic neuropathy and enteric glia in the ileum in rats.

METHODS

Male Wistar rats were divided into four groups: normoglycemics (N), normoglycemics supplemented with L: -glutamine (NG), diabetics (D), and diabetics supplemented with L: -glutamine (DG). After 120 days, the ileums were processed for HuC/D and S100 immunohistochemistry. Quantitative and morphometric analysis was performed.

RESULTS

Diabetes significantly reduced the number of HuC/D-immunoreactive myenteric neurons per unit area and per ganglion in group D compared with normoglycemic animals (group N). L: -Glutamine (2%) prevented neuronal death induced by diabetes (group DG) compared with group D. The glial density per unit area did not change with diabetes (group D) but was significantly reduced after L: -glutamine supplementation (groups NG and DG). Ganglionic glial density was similar among the four groups. The neuronal area was not altered in groups D and DG. Glial size was reduced in group D; this was reversed by L: -glutamine supplementation (group DG).

CONCLUSIONS

We concluded that 2% L: -glutamine had neuroprotective effects directly on myenteric neurons and indirectly through glial cells, which had gliatrophic effects.

Bladder, bowel, and sexual dysfunction in Parkinson's disease

Bladder dysfunction (urinary urgency/frequency), bowel dysfunction (constipation), and sexual dysfunction (erectile dysfunction) (also called “pelvic organ” dysfunctions) are common nonmotor disorders in Parkinson's disease (PD). In contrast to motor disorders, pelvic organ autonomic dysfunctions are often nonresponsive to levodopa treatment. The brain pathology causing the bladder dysfunction (appearance of overactivity) involves an altered dopamine-basal ganglia circuit, which normally suppresses the micturition reflex. By contrast, peripheral myenteric pathology causing slowed colonic transit (loss of rectal contractions) and central pathology causing weak strain and paradoxical anal sphincter contraction on defecation (PSD, also called as anismus) are responsible for the bowel dysfunction. In addition, hypothalamic dysfunction is mostly responsible for the sexual dysfunction (decrease in libido and erection) in PD, via altered dopamine-oxytocin pathways, which normally promote libido and erection. The pathophysiology of the pelvic organ dysfunction in PD differs from that in multiple system atrophy; therefore, it might aid in differential diagnosis. Anticholinergic agents are used to treat bladder dysfunction in PD, although these drugs should be used with caution particularly in elderly patients who have cognitive decline. Dietary fibers, laxatives, and “prokinetic” drugs such as serotonergic agonists are used to treat bowel dysfunction in PD. Phosphodiesterase inhibitors are used to treat sexual dysfunction in PD. These treatments might be beneficial in maximizing the patients' quality of life.

Clinical utility of colonic and anorectal manometry in chronic constipation

Constipation is one of the most common digestive problems in North America with significant psychosocioeconomic implications. It is caused by either a primary disorder of colonic and anorectal function or by many secondary conditions such as constipating drugs, metabolic disorders and other colorectal problems. Given the heterogeneity of problems that cause constipation, defining the underlying pathophysiology is increasingly being recognized as a key step toward optimal management. Colonic manometry with sensation and tone assessment (barostat) and anorectal manometry with rectal sensation and compliance assessment and balloon expulsion test can provide a comprehensive evaluation of colonic and anorectal sensorimotor function and facilitate a diagnosis of slow transit constipation, dyssynergic defecation or irritable bowel syndrome, or an overlap of these disorders. This review provides a critical appraisal of the role of manometric techniques toward augmenting our understanding of colonic and anorectal physiology, both in health and constipation and discussing their clinical utility in the diagnosis and management of chronic constipation.

Colchicine is effective for short-term treatment of slow transit constipation: a double-blind placebo-controlled clinical trial

PURPOSE

Although colchicine has been tested in clinical trials for treatment of constipation, the index groups in those trials were composed of special patient groups with developmental neuromuscular defects or failed surgical management. The aim of this study is to investigate the efficacy of colchicine in patients with refractory slow transit constipation.

MATERIALS AND METHODS

Sixty patients with chief complaint of chronic constipation due to slow transit consented to be included in the double-blind placebo-controlled clinical trial. These patients were randomly divided into two groups (each containing 30 patients) to receive either colchicine, 1 mg QD, (group A) or placebo (group B) for 2 months. At the end of the study, Knowles-Eccersly-Scot symptom (KESS, a valid technique to assist in the diagnosis and evaluation of symptoms in constipation) scores were compared between the case and control groups.

RESULTS

The mean KESS score measured at the end of 2 months was 11.67 +/- 3.91 for colchicine and 18.66 +/- 3.72 for placebo group (p = 0.0001).

CONCLUSION

This trial shows that low-dose colchicine is effective in treatment of slow transit constipation.

Function and dysfunction of the colon and anorectum in adults: working team report of the Swedish Motility Group (SMoG)

Symptoms of fecal incontinence and constipation are common in the general population. These can, however, be unreliably reported and are poorly discriminatory for underlying pathophysiology. Furthermore, both symptoms may coexist. In the elderly, fecal impaction always must be excluded. For patients with constipation, colon transit studies, anorectal manometry and defecography may help to identify patients with slow-transit constipation and/or pelvic floor dysfunction. The best documented medical treatments for constipation are the macrogols, lactulose and isphagula. Evolving drugs include lubiprostone, which enhances colonic secretion by activating chloride channels. Surgery is restricted for a highly selected group of patients with severe slow-transit constipation and for those with large rectoceles that demonstrably cause rectal evacuatory impairment. For patients with fecal incontinence that does not resolve on antidiarrheal treatment, functional and structural evaluation with anorectal manometry and endoanal ultrasound or magnetic resonance (MR) of the anal canal may help to guide management. Sacral nerve stimulation is a rapidly evolving alternative when other treatments such as biofeedback and direct sphincter repair have failed. Advances in understanding the pathophysiology as a guide to treatment of patients with constipation and fecal incontinence is a continuing important goal for translational research. The content of this article is a summary of presentations given by the authors at the Fourth Meeting of the Swedish Motility Group, held in Gothenburg in April 2007.

Contributions of pain sensitivity and colonic motility to IBS symptom severity and predominant bowel habits

OBJECTIVES

Irritable bowel syndrome (IBS) patients show pain hypersensitivity and hypercontractility in response to colonic or rectal distention. Aims were to determine whether predominant bowel habits and IBS symptom severity are related to pain sensitivity, colon motility, or smooth muscle tone.

METHODS

One hundred twenty-nine patients classified as IBS with diarrhea (IBS-D, N = 44), IBS with constipation (IBS-C, N = 29), mixed IBS (IBS-M, N = 45), and unspecified IBS (IBS-U, N = 11) based on stool consistency, and 30 healthy controls (HC) were studied. A manometric catheter containing a 600-mL capacity plastic bag was positioned in the descending colon. Pain threshold was assessed using a barostat. Motility was assessed for 10 min with the bag minimally inflated (individual operating pressure [IOP]), 10 min at 20 mmHg above the IOP, and for 15-min recovery following bag inflation. Motility was also recorded for 30 min following an 810-kcal meal.

RESULTS

Compared with HC, IBS patients had lower pain thresholds (medians 30 vs 40 mmHg, P < 0.01), but IBS subtypes were not different. IBS symptom severity was correlated with pain thresholds (rho =-0.36, P < 0.001). During distention, the motility index (MI) was significantly higher in IBS compared with HC (909 +/- 73 vs 563 +/- 78, P < 0.01). Average barostat bag volume at baseline was higher (muscle tone lower) in HC compared with IBS-D and IBS-M but not compared with IBS-C. The baseline MI and bag volume differed between IBS-D and IBS-C and correlated with symptoms of abdominal distention and dissatisfaction with bowel movements. Pain thresholds and MI during distention were uncorrelated.

CONCLUSIONS

Pain sensitivity and colon motility are independent factors contributing to IBS symptoms. Treatment may need to address both, and to be specific to predominant bowel habit.

Functional outcomes of two types of subtotal colectomy for slow-transit constipation: ileosigmoidal anastomosis and cecorectal anastomosis

BACKGROUND

Some patients with severe slow-transit constipation may benefit from subtotal colectomy, but there is no consensus on standard operative mode. The aim of the study was to compare the functional outcomes of subtotal colectomy with cecorectal anastomosis (CRA) with those of subtotal colectomy with ileosigmoidal anastomosis (ISA) in patients with severe slow-transit constipation.

METHODS

Records of 79 patients who received preoperative investigation to confirm slow transit at our institution from 1989 to 2004 and subsequently received colectomy with CRA (n = 34) or colectomy with ISA (n = 45) were reviewed. The mean follow-up was 2 years (range 1-15).

RESULTS

Postoperative defecation frequency increased and symptoms such as bloating and abdominal pain decreased in both groups. More CRA patients than ISA patients experienced persistent constipation and continued using laxatives or enemas at the 12-month follow-up. More ISA patients (93.3%) than CRA patients (73.5%) were satisfied with the procedure, whereas some patients in both groups complained of excessively high stool frequency and fecal incontinence.

CONCLUSION

Both CRA and ISA procedures increase the number of bowel movements; however, ISA results in higher defecation frequency, less use of laxatives and enemas, and higher patient satisfaction.

Bladder and bowel dysfunction in Parkinson's disease

Bladder dysfunction (urinary urgency/frequency) and bowel dysfunction (constipation) are common non-motor disorders in Parkinson's disease (PD). In contrast to motor disorder, the pelvic autonomic dysfunction is often non-responsive to levodopa treatment. Brain pathology mostly accounts for the bladder dysfunction (appearance of overactivity) via altered dopamine-basal ganglia circuit, which normally suppresses the micturition reflex. In contrast, peripheral enteric pathology mostly accounts for the bowel dysfunction (slow transit and decreased phasic contraction) via altered dopamine-enteric nervous system circuit, which normally promotes the peristaltic reflex. In addition, weak strain and paradoxical anal contraction might be the results of brain pathology. Pathophysiology of the pelvic organ dysfunction in PD differs from that in multiple system atrophy; therefore it might aid the differential diagnosis. Drugs to treat bladder dysfunction in PD include anticholinergic agents. Drugs to treat bowel dysfunction in PD include dietary fibers, peripheral dopaminergic antagonists, and selective serotonergic agonists. These treatments might be beneficial not only in maximizing patients' quality of life, but also in promoting intestinal absorption of levodopa and avoiding gastrointestinal emergency.

Intestinal gas retention in patients with idiopathic slow-transit constipation

Patients with slow-transit constipation (STC) have delayed colonic transit for solid und liquid bowel contents but intestinal gas handling has not been studied so far. Different nutrients influence motor and sensory gut function. We hypothesized that, in patients with STC, alteration of regulatory mechanisms may result in impaired intestinal gas dynamics. On 3 separate days, validated gas challenge was performed in 10 STC patients and 10 volunteers during duodenal saline, lipids, or intravenous glucose. During saline only 60% +/- 8% of gas was cleared by STC patients after 60-min gas infusion, vs. 91% +/- 2% by controls (P < 0.001). Acute hyperglycemia or lipids did not change intestinal gas dynamics in these patients (saline infusion), but compared to healthy subjects, significant intestinal gas retention occurred. In STC, disturbances of intestinal gas dynamics include basal intestinal gas retention, and this is virtually not affected by acute hyperglycemia or duodenal lipids.

Diagnostic testing in patients with chronic constipation

During the past few years, significant developments have taken place in the understanding and diagnosis of defecation disorders. Several innovative manometric, neurophysiologic, and radiologic techniques have been discovered, which have improved the accuracy of identifying the neuromuscular and pathophysiologic mechanisms of chronic constipation. Such approaches have led to improved management of these patients. In this review, we summarize and highlight recent advances in the utility of diagnostic testing of chronic constipation.

Simultaneous assessment of the intraluminal pressure and transit time of the colon using a telemetry technique

Colonic motility disorders are common conditions. However, our understanding of normal and pathological motor functions of the colon remains limited, mainly due to the technical difficulties in accessing this organ for study. To investigate colonic motility under normal physiological conditions, we have developed a novel monitoring system based on a telemetry technique. The system is capable of prolonged and noninvasive measurement of intraluminal pressure changes and transit time of intra-colonic contents. To test the in vivo performance of the monitoring system, 15 healthy volunteers and 15 patients with functional constipation (FC) participated in this study. A single-use telemetry capsule embedded with sensors was ingested by the subjects. The capsule is capable of transmitting colonic pressure and temperature wirelessly. The time of the telemetry capsule entering the segmental colon was detected by ultrasonic detection of the batteries in capsule. Pressure recordings confirmed in general a circadian behavior of colonic motility, as well as its response to waking and meals. In the FC patients, the contractile response to morning awakening and meal ingestion was significantly lower compared to the controls. The transit time measured using this method agreed with the time calculated from radiopaque markers (r = 0.89, p < 0.05). The clinical study proved both the reliability and the noninvasiveness of the system. This capsule-style manometric system may represent a useful tool for the study of physiology and pathology of colonic motor disorders.

A novel biomagnetic approach to study caecocolonic motility in humans

Motility patterns play a major role in human colonic functions; however, its physiological significance is poorly understood. Several studies have been introducing the Alternating Current Biosusceptometry (ACB) as a valuable tool in gastroenterology and pharmaceutical research. Using gold standard techniques, great effort has been made to validate ACB as a method for measuring gastrointestinal motility in humans and animals. The aim of this study was to evaluate caecocolonic motility and its response to a meal in healthy volunteers. The results showed a dominant frequency of 3.17 +/- 0.13 cycles per minute (mean +/- SD) that remained unchanged even after a standardized meal (P > 0.01). The colonic response to a meal was recorded as a considerable increase in amplitude, reflected by motility index (P < 0.01) and was observed for all the volunteers. The caecocolonic motility could be assessed by the ACB providing new insights into physiological patterns of motility. Moreover, the method is non-invasive, radiation-free, cost-effective and independent of bowel preparation.

Is pseudomelanosis coli a marker of colonic neuropathy in severely constipated patients?

AIMS

To study relationships between the number of pseudomelanosis coli cells and that of colonic enteric neurons and interstitial cells of Cajal, which are significantly reduced compared with controls in severely constipated patients. Pseudomelanosis coli is frequent in patients using anthraquinone laxatives. It is not known whether the prolonged use of these compounds damages the enteric nervous system in constipated patients.

PATIENTS AND METHODS

The relationship between the number of pseudomelanosis coli cells and that of colonic enteric neurons (as well as that of apoptotic enteric neurons) and of interstitial cells of Cajal was assessed by histological and immunohistochemical methods in 16 patients with chronic use of anthraquinone laxatives undergoing surgery for severe constipation unresponsive to medical treatment. No relationship was found between the number of pseudomelanosis coli cells and that of enteric neurons (and that of the apoptotic ones), nor of interstitial cells of Cajal, in either the submucosal or the myenteric plexus.

CONCLUSION

The use of anthraquinone laxatives, leading to the appearance of pseudomelanosis coli, is probably not related to the abnormalities of the enteric nervous system found in severely constipated patients.

Defecation disorders: neuromuscular aspects and treatment

Chronic constipation and fecal incontinence affect 20% of the population and are more prevalent in women, the elderly, those of lower socioeconomic status, and nursing home residents. These disorders pose a significant economic burden and affect quality of life. During the past decade, significant strides have been made in the understanding and treatment of defecation disorders, which have led to real advances in the management of these disorders. These treatments include biofeedback therapy, tegaserod, and lubiprostone for chronic constipation.

Slow transit constipation: A functional disorder becomes an enteric neuropathy

Slow transit constipation has been traditionally considered and classified as a functional disorder. However, clinical and manometric evidence has been accumulating that suggests how most of the motility alterations in STC might be considered of neuropathic type.In addition, further investigations showed that subtle alterations of the enteric nervous system, not evident to conventional histological examination, may be present in these patients. In the present article we will discuss these evidences, and will try to put them in relation with the abnormal motor function of the large bowel documented in this pathological condition.