Novel concepts in the diagnosis, pathophysiology and management of idiopathic megabowel

Clinical features and outcomes of adult idiopathic megarectum

OBJECTIVE

Idiopathic megarectum is characterized by abnormal, pronounced rectal dilatation in the absence of identifiable organic pathology. Idiopathic megarectum is uncommon and under-recognized. This study aims to describe the clinical features and management of idiopathic megarectum.

METHODS

A retrospective review was undertaken on patients diagnosed with idiopathic megarectum with or without idiopathic megacolon over a 14-year period until 2021. Patients were identified from the hospital's International Classification of Diseases codes, and pre-existing clinic patient databases. Patient demographics, disease characteristics, healthcare utilization and treatment history data were collected.

RESULTS

Eight patients with idiopathic megarectum were identified; half of the patients were female, with the median age of symptom onset being 14 years (interquartile range [IQR] 9-24). The median rectal diameter measured was 11.5 cm (IQR 9.4-12.1). The most common presenting symptom was constipation, bloating and faecal incontinence. All patients required prior sustained periods of regular phosphate enemas and 88% were using ongoing oral aperients. Concomitant anxiety and or depression were found in 63% of patients and 25% were diagnosed with an intellectual disability. Healthcare utilization was high with a median of three emergency department presentations or ward admissions related to idiopathic megarectum per patient over the follow-up period; 38% of patients required surgical intervention during the period of follow-up.

CONCLUSION

Idiopathic megarectum is uncommon and associated with significant physical and psychiatric morbidity and high healthcare utilization.

Idiopathic Megacolon-Short Review

INTRODUCTION

Idiopathic megacolon (IM) is a rare condition with a more or less known etiology, which involves management challenges, especially therapeutic, and both gastroenterology and surgery services. With insufficiently drawn out protocols, but with occasionally formidable complications, the condition management can be difficult for any general surgery team, either as a failure of drug therapy (in the context of a known case, initially managed by a gastroenterologist) or as a surgical emergency (in which the diagnostic surprise leads additional difficulties to the tactical decision), when the speed imposed by the severity of the case can lead to inadequate strategies, with possibly critical consequences.

METHOD

With such a motivation, and having available experience limited by the small number of cases (described by all medical teams concerned with this pathology), the revision of the literature with the update of management landmarks from the surgical perspective of the pathology appears as justified by this article.

RESULTS

If the diagnosis of megacolon is made relatively easily by imaging the colorectal dilation (which is associated with initial and/or consecutive clinical aspects), the establishing of the diagnosis of idiopathic megacolon is based in practice almost exclusively on a principle of exclusion, and after evaluating the absence of some known causes that can lead to the occurrence of these anatomic and clinical changes, mimetically, clinically, and paraclinically, with IM (intramural aganglionosis, distal obstructions, intoxications, etc.). If the etiopathogenic theories, based on an increase in the performance of the arsenal of investigations of the disease, have registered a continuous improvement and an increase of objectivity, unfortunately, the curative surgical treatment options still revolve around the same resection techniques. Moreover, the possibility of developing a form of etiopathogenic treatment seems as remote as ever.

Idiopathic megacolon and megarectum in an adult treated with laparoscopic modified Duhamel procedure

Idiopathic megacolon (IMC) and idiopathic megarectum (IMR) describe an abnormality of the colon or rectum, characterised by a permanent dilatation of the bowel diameter in the absence of an identifiable cause. We present a 23-year-old woman with chronic constipation and excessive straining during defecation who presented at the emergency department in partial gut obstruction with a palpable fecaloma. Manual faecal disimpaction and a sigmoid loop colostomy was initially done. A full thickness rectal biopsy was positive for ganglion cells. Further workup led to the diagnosis of chronic IMC and IMR. The patient underwent laparoscopic modified Duhamel procedure, with an uneventful postoperative course.

Laparoscopic-assisted colectomy with Duhamel procedure for idiopathic megacolon in adults: a retrospective study

BACKGROUND

Idiopathic megacolon (IMC) is an uncommon disease in adults. To date, only a few laparoscopic experiences and functional outcomes of IMC have been reported. This study was to retrospectively analyse our 12 year surgical experience and functional outcomes in adult patients with IMC.

METHODS

A 12-year retrospective study from October 2006 to November 2018 was performed for patients with IMC who underwent surgical interventions. Patients who underwent laparoscopic-assisted colectomy and Duhamel procedure with ileorectal or colorectal anastomosis were collected. Clinical data of surgery and functional outcomes were analysed.

RESULTS

A total of 13 patients who underwent surgical interventions were included in the study. Seven patients underwent laparoscopic total colectomy with ileorectal anastomosis (Duhamel procedure), one patient underwent laparoscopic total colectomy with end ileostomy because of acute intestinal obstruction, while five other patients underwent laparoscopic segmental colectomy with colorectal anastomosis (Duhamel procedure). The mean operative time was 181.6 min (range 150-246). The mean estimated blood loss was 75.6 ml (range 40-200). The mean postoperative hospital stay was 8.2 days (range 6-13). There was no conversion to an open procedure and no surgical mortality. Postoperative diarrhoea was the most prominent complaint during the early period after total colectomy. All patients showed adaptation to the defaecation frequency 3-6 months postoperatively, and had a good quality of life in long-term follow-up.

CONCLUSION

Laparoscopic-assisted colectomy with Duhamel procedure is a safe and efficient technique for IMC in adults. The scope of colon resection and the type of anastomosis should be individually selected.

An unusual cause of idiopathic megacolon in a juvenile: A case report

RATIONALE

Idiopathic megacolon (IMC) is a rare condition in young children. The association of indigestible food and IMC has never been mentioned in literature.

PATIENT CONCERNS

An 11-year-old boy reported with a 1-year duration of intermittent constipation and abdominal distension after having eaten a large amount of fried sticky rice in 1 consumption.

DIAGNOSES

Chronic low colonic obstruction, IMC and malnutrition.

INTERVENTIONS

This patient was managed conservatively for 1 week at first. Then he underwent loop ileostomy since conservative therapy was poorly tolerated. Enteral decompression, gut biopsy, peritoneal lavage, and drainage were performed in the same procedure.

OUTCOMES

Rapid weight gain was observed 4 months after operation.

LESSONS

IMC is difficult to diagnose due to the lack of specific clinical manifestations and pathological features. The protocols for management of IMC remains controversial. To achieve a good long-term outcome, early intervention is recommended.

Systematic review with meta-analysis: defecography should be a first-line diagnostic modality in patients with refractory constipation

BACKGROUND

Defecography is considered the reference standard for the assessment of pelvic floor anatomy and function in patients with a refractory evacuation disorder. However, the overlap of radiologically significant findings seen in patients with chronic constipation (CC) and healthy volunteers is poorly defined.

AIM

To systematically review rates of structural and functional abnormalities diagnosed by barium defecography and/or magnetic resonance imaging defecography (MRID) in patients with symptoms of CC and in healthy volunteers.

METHODS

Electronic searches of major databases were performed without date restrictions.

RESULTS

From a total of 1760 records identified, 175 full-text articles were assessed for eligibility. 63 studies were included providing data on outcomes of 7519 barium defecographies and 668 MRIDs in patients with CC, and 225 barium defecographies and 50 MRIDs in healthy volunteers. Pathological high-grade (Oxford III and IV) intussuscepta and large (>4 cm) rectoceles were diagnosed in 23.7% (95% CI: 16.8-31.4) and 15.9% (10.4-22.2) of patients, respectively. Enterocele and perineal descent were observed in 16.8% (12.7-21.4) and 44.4% (36.2-52.7) of patients, respectively. Barium defecography detected more intussuscepta than MRID (OR: 1.52 [1.12-2.14]; P = 0.009]). Normative data for both barium defecography and MRID structural and functional parameters were limited, particularly for MRID (only one eligible study).

CONCLUSIONS

Pathological structural abnormalities, as well as functional abnormalities, are common in patients with chronic constipation. Since structural abnormalities cannot be evaluated using nonimaging test modalities (balloon expulsion and anorectal manometry), defecography should be considered the first-line diagnostic test if resources allow.

Symptoms and diagnostic criteria of acquired Megacolon - a systematic literature review

BACKGROUND

Acquired Megacolon (AMC) is a condition involving persistent dilatation and lengthening of the colon in the absence of organic disease. Diagnosis depends on subjective radiological, endoscopic or surgical findings in the context of a suggestive clinical presentation. This review sets out to investigate diagnostic criteria of AMC.

METHODS

The literature was searched using the databases - PubMed, Medline via OvidSP, ClinicalKey, Informit and the Cochrane Library. Primary studies, published in English, with more than three patients were critically appraised based on study design, methodology and sample size. Exclusion criteria were studies with the following features: post-operative; megarectum-predominant; paediatric; organic megacolon; non-human; and failure to exclude organic causes.

RESULTS

A review of 23 articles found constipation, abdominal pain, distension and gas distress were predominant symptoms. All ages and both sexes were affected, however, symptoms varied with age. Changes in anorectal manometry, histology and colonic transit are consistently reported. Studies involved varying patient numbers, demographics and data acquisition methods.

CONCLUSIONS

Outcome data investigating the diagnosis of AMC must be interpreted in light of the limitations of the low-level evidence studies published to date. Proposed diagnostic criteria include: (1) the exclusion of organic disease; (2) a radiological sigmoid diameter of ~ 10 cm; (3) and constipation, distension, abdominal pain and/or gas distress. A proportion of patients with AMC may be currently misdiagnosed as having functional gastrointestinal disorders. Our conclusions are inevitably tentative, but will hopefully stimulate further research on this enigmatic condition.

The correlation between diverticulosis and redundant colon

BACKGROUND

Diverticulosis and redundant colon are colonic conditions for which underlying pathophysiology, management and prevention are poorly understood. Historical papers suggest an inverse relationship between these two conditions. However, no further attempt has been made to validate this relationship. This study set out to assess the correlation between diverticulosis and colonic redundancy.

METHODS

Redundant colon, diverticulosis and patient demographics were recorded during colonoscopy. Multivariate binary logistic regression was performed with redundant colon as the dependent variable and age, gender and diverticulosis as independent variables. Nagelkerke R ² and a receiver operator curve were calculated to assess goodness of fit and internally validate the multivariate model.

RESULTS

Redundant colon and diverticulosis were diagnosed in 31 and 113 patients, respectively. The probability of redundant colon was increased by female gender odds ratio (OR) 8.4 (95% CI 2.7-26, p = 0.00020) and increasing age OR 1.7 (95% CI 1.1-2.6, p = 0.017). Paradoxically, diverticulosis strongly reduced the probability of redundant colon with OR of 0.12 (95% CI 0.42-0.32, p = 0.000039). The Nagelkerke R ² for the multivariate model was 0.29 and the area under the curve at ROC analysis was 0.81 (95% CI 0.73-0.90 p-value 3.1 × 10^-8).

CONCLUSIONS

This study found an inverse correlation between redundant colon and diverticulosis, supporting the historical suggestion that the two conditions rarely occur concurrently. The underlying principle for this relationship remains to be found. However, it may contribute to the understanding of the aetiology and pathophysiology of these colonic conditions.

Histopathologic findings in patients with idiopathic megacolon: a comparison between dilated and non-dilated loops

BACKGROUND

Idiopathic megacolon (IMC) is an intractable motility disorder in which chronic symptoms of colonic dysmotility appear with no mechanical cause. Although a pathological analysis is essential to understand the mechanism of IMC, no study has compared the histopathologic findings between dilated and non-dilated loops in IMC cases, and little is known about the proportion of each disease subtype.

METHODS

Fifty-three full-thickness samples (dilated loops, n = 31; non-dilated loops, n = 22) from 31 IMC cases and 16 samples (dilated loops; n = 8, non-dilated loops; n = 8) from eight controls were collected. All the samples were stained with hematoxylin-eosin (HE), Hu C/D antibody, and CD117 antibody to assess degenerative myopathy, degenerative neuropathy, inflammatory neuropathy, hypoganglionosis, and mesenchymopathy according to the London Classification. Findings of the dilated and non-dilated loop samples were compared, and the proportions of each subtype were analyzed.

KEY RESULTS

Based on a control study, <60 ganglion cells/cm was defined as hypoganglionosis in our series. Myopathy was observed in 11 patients (35.5%), neuropathy was in 19 patients (61.3%), and mesenchymopathy was in 10 patients (32.2%). An overlap between subtypes was observed in some cases. Surprisingly, the non-dilated loop samples exhibited very similar histopathologic abnormalities to those observed in the dilated loop samples in most cases.

CONCLUSIONS & INFERENCES

Our study is the first to compare the histopathologic findings between dilated and non-dilated loops in IMC patients. Histopathologic abnormalities precede the clinical manifestation of IMC, and may consequently lead to gradual colonic dilatation; however, detailed mechanism including dilation triggering factor needs further elucidation.

Clinical and psychosocial functioning in adolescents and young adults with anorectal malformations and chronic idiopathic constipation

BACKGROUND

Faecal incontinence (FI) and constipation occur following corrective surgery for anorectal malformations (ARMs) and in children or adults with chronic constipation without a structural birth anomaly (chronic idiopathic constipation, CIC). Such symptoms may have profound effects on quality of life (QoL). This study systematically determined the burden of FI and constipation in these patients in adolescence and early adulthood, and their effect on QoL and psychosocial functioning in comparison with controls.

METHODS

Patients with ARMs or CIC were compared with age- and sex-matched controls who had undergone appendicectomy more than 1 year previously and had no ongoing gastrointestinal symptoms. Constipation and FI were evaluated using validated Knowles-Eccersley-Scott Symptom (KESS) and Vaizey scores respectively. Standardized QoL and psychometric tests were performed in all groups.

RESULTS

The study included 49 patients with ARMs (30 male, aged 11-28 years), 45 with CIC (32 male, aged 11-30 years) and 39 controls (21 male, aged 11-30 years). The frequency of severe constipation among patients with ARMs was approximately half that seen in the CIC group (19 of 49 versus 31 of 45); however, frequencies of incontinence were similar (22 of 49 versus 21 of 45) (P < 0·001 versus controls for both symptoms). Physical and mental well-being were significantly reduced in both ARM and CIC groups compared with controls (P = 0·001 and P = 0·015 respectively), with generally worse scores among patients with CIC. Both were predicted by gastrointestinal symptom burden (P < 0·001). There were no statistically significant differences in state or trait psychiatric morbidity between groups.

CONCLUSION

FI and constipation are major determinants of poor QoL in adolescents and young adults with ARMs and in those with CIC.

Nationwide survey on adult type chronic intestinal pseudo-obstruction in surgical institutions in Japan

BACKGROUND

No appropriate management of chronic intestinal pseudo-obstruction (CIP) has been established.

PATIENTS AND METHODS

The clinicopathological parameters of 103 cases collected by a nationwide questionnaire study were reviewed.

RESULTS

The CIP cases were primary in 86 (83%) cases and secondary in 15 (15%) cases. The age of onset of the primary type was significantly younger than that of the secondary type (p = 0.011). The diseased segments of the bowel were the large bowel in 60 (58%), the small bowel in 17 (17%), and both in 23 (22%) cases, respectively. Abdominal distension and pain were common symptoms regardless of the types of the diseased bowel; however, constipation was frequently seen in the large bowel type (p = 0.0258). Vomiting and diarrhea were seen with marginally higher frequency in the small bowel type (p = 0.0569, 0.0642). Surgical treatment was most effective in the large bowel type, less effective in the small bowel type, and least effective in the large and small bowel type. The prognosis of the primary CIP was significantly better than that of the secondary CIP (p = 0.033).

CONCLUSIONS

The segments of the diseased bowels should be considered in determining the indications for surgical treatments in CIP patients.

Rectal sensorimotor dysfunction in constipation

The pathophysiological mechanisms underlying chronic constipation in both adults and children remain to be unravelled. This is a not inconsiderable challenge, but is fundamental to improving management of such patients. Rectal sensorimotor function, which encompasses both sensation and motility, as well as biomechanical components (compliance, capacity), is now strongly implicated in the pathogenesis of constipation. Rectal hyposensitivity, rectal hypercompliance, increased rectal capacity, rectal motor dysfunction (phasic contractility and tone), and altered rectoanal reflex activity are all found in constipated patients, particularly in association with 'functional' disorders of defaecation (i.e. pelvic floor dyssynergia). This review covers contemporary understanding of how components of rectal sensorimotor function may contribute to symptom development in both adult and paediatric populations. The complex interaction between sensory/motor/biomechanical domains, and how best to measure these functions are addressed, and where data exist, the impact of sensorimotor dysfunction on therapeutic outcomes is highlighted.

Can "functional" constipation be considered as a form of enteric neuro-gliopathy?

Constipation has been traditionally viewed and classified as a functional or idiopathic disorder. However, evidence has been accumulating that suggests how constipation might be considered as due to abnormalities of the enteric nervous system, since alterations of this system, not evident in conventional histological examination, may be present in these patients. These abnormalities often consist in decrease or loss of the enteric glial cells, a pathological finding present in most types of constipation so far investigated. In this article we will discuss these evidences, and will try to consider constipation no more as a simple functional or idiopathic disorder but as a form of enteric neuro-gliopathy.

Do gastrointestinal transit times and colonic dimensions change with time since spinal cord injury?

STUDY DESIGN

Long-term follow-up study.

OBJECTIVES

To determine whether gastrointestinal transit times (GITTs) and colonic dimensions change during the first or subsequent decades after spinal cord injury (SCI).

SETTING

Aarhus University Hospital, Denmark.

METHODS

GITT and colonic dimensions were evaluated by means of radio-opaque markers. Group A (n=12) was investigated 1 year after SCI and again 13 (range 11-14) years later. Group B (n=10) was studied 19 (range 9-36) years after injury and again 12 (range 11-12) years later. All had been treated with conservative bowel management.

RESULTS

In group A, the median GITT 1 year after injury was 4.3 (range 1.1-6.5) days and 13 years later, it was 3.2 (range 1.3-6.5) days, P=0.96. In group B, the median GITT 19 year after injury was 3.4 (range 0.6-5.9) days and 12 years later, it was 3.2 (range 1.9-5.5) days, P=0.77. None of the two groups experienced a significant change in the diameter of the caecum/ascending colon, transverse colon, descending colon or the sigmoid during long-term follow-up. Megacolon was present in four patients at baseline and in five at follow-up.

CONCLUSION

GITTs and colonic dimensions did not change, neither during the first decade nor long after SCI.

Therapy-refractory gastrointestinal motility disorder in a child with c-kit mutations

Constipation and fecal impaction are frequent and distressing complaints in pediatric gastroenterology. Especially in neurologically handicapped children, treatment of severe forms of slow-transit constipation (STC) can be difficult. In the majority of cases, STC is of unknown etiology. However, in recent years, there is growing evidence that interstitial cells of Cajal (ICCs), which serve as electrical pacemakers and generate spontaneous electrical slow waves in the gastrointestinal tract, might play an important role in the pathophysiology of STC. It remains unclear whether morphological ICC alterations seen in affected patients are based on congenital developmental anomalies, or whether they are a consequence of long-term constipation with secondary damage of the gastrointestinal nervous system. To the best of our knowledge, we present the first case of a patient with histological alterations in ICC morphology who displayed multiple alterations of c-kit at the level of mRNA. The protein encoded by c-kit is the receptor tyrosine kinase Kit (CD117), which is crucial for development and function of ICCs. Therefore, these findings provide a new explanation for congenital alterations of ICC development that result in gastrointestinal motility disorders.

Surgical management of constipation

This review addresses the range of operations suggested to be of contemporary value in the treatment of constipation with critical evaluation of efficacy data, complications, patient selection, controversies and areas for future research.

Pathophysiology of evacuation disorders

This review details our contemporary knowledge of the mechanisms underlying evacuatory disorders. There is confusion concerning terminology and classification, which is based upon both an incomplete understanding of the multiple mechanisms involved in evacuation, and that current tests to investigate it are not physiological. Nevertheless, despite the need for more research, significant advances have been made and current assessments can direct therapy.

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.

Gastrointestinal neuromuscular pathology: guidelines for histological techniques and reporting on behalf of the Gastro 2009 International Working Group

The term gastrointestinal neuromuscular disease describes a clinically heterogeneous group of disorders of children and adults in which symptoms are presumed or proven to arise as a result of neuromuscular, including interstitial cell of Cajal, dysfunction. Such disorders commonly have impaired motor activity, i.e. slowed or obstructed transit with radiological evidence of transient or persistent visceral dilatation. Whilst sensorimotor abnormalities have been demonstrated by a variety of methods in these conditions, standards for histopathological reporting remain relatively neglected. Significant differences in methodologies and expertise continue to confound the reliable delineation of normality and specificity of particular pathological changes for disease. Such issues require urgent clarification to standardize acquisition and handling of tissue specimens, interpretation of findings and make informed decisions on risk-benefit of full-thickness tissue biopsy of bowel or other diagnostic procedures. Such information will also allow increased certainty of diagnosis, facilitating factual discussion between patients and caregivers, as well as giving prognostic and therapeutic information. The following report, produced by an international working group, using established consensus methodology, presents proposed guidelines on histological techniques and reporting for adult and paediatric gastrointestinal neuromuscular pathology. The report addresses the main areas of histopathological practice as confronted by the pathologist, including suction rectal biopsy and full-thickness tissue obtained with diagnostic or therapeutic intent. For each, indications, safe acquisition of tissue, histological techniques, reporting and referral recommendations are presented.

Rectal hyposensitivity: pathophysiological mechanisms

Rectal hyposensitivity (RH) relates to a diminished perception of rectal distension. It may occur due to afferent nerve dysfunction and/or secondary to abnormal structural or biomechanical properties of the rectum. The aim of this study was to determine the contribution of these underlying pathophysiological mechanisms by systematically evaluating rectal diameter, compliance and afferent nerve sensitivity in patients with RH, using methodology employed in clinical practice. The study population comprised 45 (33 women; median age 48, range 25-72 years) constipated patients (Rome II criteria) with RH and 20 with normal rectal sensitivity on balloon distension and 20 healthy volunteers. Rectal diameter was measured at minimum distending pressure during isobaric distension under fluoroscopic screening. Rectal compliance was assessed during phasic isobaric distension by measuring the slope of the pressure-volume curve. Electrical stimulation of the rectal mucosa was employed to determine afferent nerve function. Values were compared to normal ranges established in healthy volunteers. The upper limits of normal for rectal diameter, compliance and electrosensitivity were 6.3 cm, 17.9 mL mmHg(-1) and 21.3 mA respectively. Among patients with RH, rectal diameter, but not compliance, was increased above the normal range (megarectum) in seven patients (16%), two of whom had elevated electrosensitivity thresholds. Rectal diameter and compliance were elevated in 23 patients (51%), nine of whom had elevated electrosensitivity thresholds. The remaining 15 patients (33%) with RH had normal rectal compliance and diameter, all of whom had elevated electrosensitivity thresholds. Two-third of the patients with RH on simple balloon distension have elevated rectal compliance and/or diameter, suggesting that impaired perception of rectal distension is due to inadequate stimulation of the rectal afferent pathway. However, a proportion of such patients also appear to have impaired nerve function. In the remaining one-third of the patients, rectal diameter and compliance are normal, while electrosensitivity thresholds are elevated, suggestive of true impaired afferent nerve function. Identification of these subgroups of patients with RH may have implications regarding their management.

The chronic gastrointestinal manifestations of Chagas disease

Chagas disease is an infectious disease caused by the protozoan Trypanosoma cruzi. The disease mainly affects the nervous system, digestive system and heart. The objective of this review is to revise the literature and summarize the main chronic gastrointestinal manifestations of Chagas disease. The chronic gastrointestinal manifestations of Chagas disease are mainly a result of enteric nervous system impairment caused by T. cruzi infection. The anatomical locations most commonly described to be affected by Chagas disease are salivary glands, esophagus, lower esophageal sphincter, stomach, small intestine, colon, gallbladder and biliary tree. Chagas disease has also been studied in association with Helicobacter pylori infection, interstitial cells of Cajal and the incidence of gastrointestinal cancer.

Surgical treatment of patients with constipation and fecal incontinence

Patients with constipation and fecal incontinence usually come to the attention of the surgeon when conservative measures have failed to alleviate sufficiently severe symptoms. Following detailed clinical and physiologic assessment, the surgeon should tailor the procedure to specific underlying physiologic abnormalities to restore function. This article describes the rationale, indications (including patient selection), results, and current position controversies of surgical procedures for constipation and fecal incontinence, dividing these into those regarded as historical, contemporary, or evolving. Reported surgical outcome data must be interpreted with caution because for most studies the evidence is of low quality, making comparison of different procedures problematic and emphasizing the need for better designed and conducted clinical trials.

Manometric, sensorimotor, and neurophysiologic evaluation of anorectal function

With advances in diagnostic technology, it is now accepted that in the field of functional bowel disorders, symptom-based assessment is unsatisfactory as the sole means of directing therapy. A robust taxonomy based on underlying pathophysiology has been suggested, highlighting a crucial role for physiologic testing in clinical practice. A wide number of complementary investigations currently exist for the assessment of anorectal structure and function, some of which have a clinical impact in patients with functional disorders of evacuation and continence by markedly improving diagnostic yield and altering management. The techniques, limitations, measurements, and clinical use of manometric, sensorimotor, and neurophysiologic tests of anorectal function are presented.