The prevalence of small intestinal bacterial overgrowth and methane production in patients with myelomeningocele and constipation. Spinal Cord. 2014;52:61-64. [PMID: 24247567 DOI: 10.1038/sc.2013.131]

The relationship between small intestinal bacterial overgrowth and constipation in children - a comprehensive review

Small intestinal bacterial overgrowth (SIBO) is characterized by an increase in the bacterial population of the small intestine due to an imbalance between the amount of bacteria and the intestinal barrier. Pediatric SIBO presents with a wide spectrum of symptoms, ranging from mild gastrointestinal complaints to malabsorption or malnutrition. Breath tests are commonly used as noninvasive diagnostic tools for SIBO, but a standardized methodology is currently unavailable. Intestinal flora produces methane which slows intestinal transit and increases the contractile activity of small intestine. Emerging literature suggests a correlation between overgrowth of methanogenic bacteria in the intestines and constipation. Treatment of SIBO involves administration of antibacterial therapy in addition to management of underlying conditions and optimal dietary adjustments. However, research on antibiotic treatment for pediatric patients with constipation and SIBO is limited and has yielded conflicting results. In the current review, we summarize the state-of-the-art of the field and discuss previous treatment attempts and currently used regimens for SIBO patients with constipation, with a focus on pediatric populations.

State of the Art Bowel Management for Pediatric Colorectal Problems: Spinal Anomalies

BACKGROUND

Patients with spinal abnormalities often struggle with fecal and/or urinary incontinence (up to 87 and 92%, respectively) and require a collaborative approach to bowel management in conjunction.

METHODS

To define existing approaches and propose state-of-the-art bowel management, a literature search was performed using Medline/PubMed, Google Scholar, Cochrane, and EMBASE databases and focusing on the manuscripts published July 2013 and July 2023.

RESULTS

Patients with spinal anomalies have impaired innervation of the rectum and anal canal, decreasing the success rate from laxatives and rectal enemas. Thus, transanal irrigations and antegrade flushes are widely utilized in this group of patients. Based on spinal MRI, the potential for bowel control in these children depends on age, type, and lesion level. On referral for bowel management, a contrast study is performed to assess colonic motility and evacuation of stool, followed by a series of abdominal X-rays to define colonic emptying and adjust the regimen. The options for management include laxatives, rectal enemas, transanal irrigations, antegrade flushes, and the creation of a stoma. Approximately 22-71% of patients achieve social continence dependent on the type and level of the lesion.

CONCLUSION

Patients with spinal anomalies require a thorough assessment for continence potential and stool burden prior to initiation of bowel management. The optimal treatment option is defined according to the patient's age, anatomy, and mobility. The likelihood of independent bowel regimen administration should be discussed with the patients and their caregivers.

Prevalence, risk factors, and treatment of small intestinal bacterial overgrowth in children

Small intestinal bacterial overgrowth (SIBO) is defined as the presence of an excessive number of bacteria within the small bowel. Pediatric SIBO is a heterogeneous disorder that manifests as various symptoms ranging from mild gastrointestinal symptoms to malabsorption or malnutrition. The carbohydrate breath test is a commonly used, safe, and noninvasive diagnostic test; however, a standardized methodology is lacking. Multiple factors, such as neuromuscular disorders, systemic diseases, chronic drug use, or altered intestinal anatomy that disturb intestinal motility or induce an abnormality in the body's defense systems against intestinal bacteria, predispose children to SIBO. The high prevalence and similar symptoms of SIBO in functional gastrointestinal disorders, including irritable bowel syndrome, suggest an association between them. The principles of treatment include managing predisposing conditions, nutritional support, symptom control, and antibacterial treatment. Rifaximin is the most commonly used drug. To date, studies of antibiotic treatment in pediatric populations with irritable bowel syndrome or SIBO are lacking and have shown mixed results. Here we review the prevalence, diagnostic tests, and treatment results in pediatric populations.

Gut microbiota and pediatric patients with spina bifida and neurogenic bowel dysfunction

PURPOSE

Gut microbiota has recently been recognized to be influenced by a broad range of pathologies. Alterations of gut microbiota are known as dysbiosis and have found to be related to chronic constipation, a condition which affects also pediatric patients with spina bifida (SB).

METHODS

In this study, gut microbiota richness and composition were investigated by 16S rRNA sequencing and bioinformatic analysis in 48 SB patients (mean age, 11.9 ± 4.8 years) with secondary neurogenic constipation and 32 healthy controls (mean age, 18.0 ± 9.6 years). The study also aimed at exploring eventual effects of laxatives and transanal irrigation (TAI) adopted by SB subjects to get relief from the symptoms of neurogenic constipation.

RESULTS

Collected data demonstrated that the microbiota richness of SB patients was significantly increased compared to healthy controls, with a higher number of dominant bacteria rather than rare species. The absence of SB condition was associated with taxa Coprococcus 2, with the species C. eutactus and Roseburia, Dialister, and the [Eubacterium] coprostanoligenes group. On the other hand, the SB patients displayed a different group of positively associated taxa, namely, Blautia, Collinsella, Intestinibacter, and Romboutsia genera, the [Clostridium] innocuum group, and Clostridium sensu stricto 1. Bifidobacterium and the [Eubacterium] hallii group were also found to be positively associated with SB gut microbiome.

CONCLUSIONS

Among SB patients, the administration of laxatives and TAI did not negatively affect gut microbiota diversity and composition, even considering long-term use (up to 5 years) of TAI device.

Pediatric neurogenic bowel dysfunction: ICCS review document

INTRODUCTION

The International Children's Continence Society (ICCS) aims to improve the quality of life in children with lower urinary tract dysfunction. A substantial portion of children also have problems with bowel dysfunction. There is a lack of evidence-based information on managing neurogenic bowel dysfunction (NBD) in children.

OBJECTIVE/METHODS

The ICCS aimed to provide an up-to-date, selective, non-systematic review of NBD's definitions, assessment, and treatment.

RESULTS

Specific definitions and terminology are defined within the document. Recommendations and considerations for physical assessment, history taking, and diagnostic studies are made. Management updates, both surgical and non-surgical, are provided as well as recommendations for follow-up and monitoring of individuals with NBD.

CONCLUSION

This review of the current literature will help guide NBD management and research to improve NBD care.

The importance of dedicated colorectal team participation in the management of spina bifida and spinal cord injury patients

PURPOSE

In September 2020, the colorectal team of the International Center for Colorectal and Urogenital Care joined the spina bifida and spinal cord injury multidisciplinary clinic at Children's Hospital Colorado. Many important lessons were learned.

METHODS

A retrospective review of patients seen in the spina bifida and spinal cord injury multidisciplinary clinic from September 2020 to May 2021 was conducted. Data collected included demographics, diagnosis, pre or post-natal repair for those with myelomeningocele, whether the patient was previously seen by the colorectal team, wheelchair usage, voluntary bowel control vs. fecal incontinence, urinary control vs. clean intermittent catheterization, characteristics of contrast enema, and our proposed intervention.

RESULTS

Overall, 189 children were seen during the study period, ranging from 3 months to 20 years of age (average = 9.5 years). One hundred and two were males and 87 were females. Diagnosis included myelomeningocele (n = 153), spinal cord injury (n = 18), transverse myelitis (n = 7), sacral agenesis (n = 5), diastematomyelia (n = 2), spinal stenosis (n = 2), and tethered cord with lipoma (n = 2). Fifteen patients with myelomeningocele were repaired in-utero. One hundred and sixty patients were new to the colorectal team. Eighty-one patients were wheelchair users. One hundred and twenty-three patients suffered from fecal incontinence and needed enemas to be artificially clean for stool and thirty-eight patients had voluntary bowel movements and were clean with laxatives, suppository, or rectal stimulations. Twenty-eight patients were younger than three years of age and still in diapers. Despite a non-dilated colon on contrast enema, this population has a hypomotile colon. One hundred and twenty-eight patients required clean intermittent catheterization.

CONCLUSION

Joining the spina bifida and spinal cord injury multidisciplinary clinic allowed us to better serve this population and gave us enormous satisfaction to contribute to improve the quality of life of the patients and their parents.

LEVEL OF EVIDENCE

III.

Neurogenic bowel treatments and continence outcomes in children and adults with myelomeningocele

PURPOSE

Neurogenic bowel dysfunction (NBD) is a common comorbidity of myelomeningocele (MMC), the most common and severe form of spina bifida. The National Spina Bifida Patient Registry (NSBPR) is a research collaboration between the CDC and Spina Bifida Clinics. Fecal continence (continence) outcomes for common treatment modalities for NBD have not been described in a large sample of individuals with MMC. NSBPR patients with MMC and NBD were studied to determine variation in continence status and their ability to perform their treatment independently according to treatment modality and individual characteristics.

METHODS

Continence was defined as < 1 episode of incontinence per month. Eleven common treatments were evaluated. Inclusion criteria were established diagnoses of both MMC and NBD, as well as age ⩾ 5 years (n= 3670). Chi-square or exact statistical tests were used for bivariate analyses. Logistic regression models were used to estimate the odds of continence outcomes by age, sex, race/ethnicity, level of motor function, and insurance status.

RESULTS

At total of 3670 members of the NSBPR met inclusion criteria between November 2013 and December 2017. Overall prevalence of continence was 45%. Prevalence ranged from 40-69% across different treatments. Among continent individuals, 60% achieved continence without surgery. Antegrade enemas were the most commonly used treatment and had the highest associated continence rate. Ability to carry out a treatment independently increased with age. Multivariable logistic regression showed significantly higher odds of continence among individuals aged ⩾ 12 years, female, non-Hispanic white, and with private insurance.

Utility estimation for neurogenic bowel dysfunction in the general population

BACKGROUND

Neurogenic bowel dysfunction (NBD) affects over 80% of individuals with spina bifida causing bowel incontinence and/or constipation. NBD is also associated with decreased quality of life, depression, anxiety, and decreased employment/educational attainment. Because NBD is a life-altering condition without a cure, understanding the utility of different health states related to NBD would aid clinicians as they try to counsel families regarding management options and to better understand the quality of life associated with disease management.

OBJECTIVE

To elicit utility scores for NBD using an online community sample.

STUDY DESIGN

A cross-sectional anonymous survey was completed by 1534 voluntary participants via an online platform (Amazon Mechanical Turk (MTurk, http://www.mturk.com/)), representing an 87% response rate. The survey presented hypothetical scenarios that asked respondents to imagine themselves as an individual living with NBD or as the caretaker of a child with NBD. The time trade-off (TTO) method was used to estimate a utility score, and outcomes for each scenario were calculated using median and IQR. Univariate comparisons of distributions of TTO for demographic data were made using Kruskal-Wallis tests.

RESULTS

The median utility score for NBD was 0.84 [0.70-0.92]. Participants reported that they would give up a median of 5 years of their own life, to prevent NBD in themselves of their child. Utility values for child scenarios were significantly different when stratified by age, gender, race, parental status, marital status, and income. Stratification by current health status did not yield significantly different utility values.

DISCUSSION

Study findings are comparable with other TTO-determined utility values of moderately severe disease states, including severe persistent asthma (0.83), moderate seizure disorder (0.84) and mild mental retardation (0.84). The significant variations in utility values based on age, gender, race, parent status, partner/marital status and income variables existed in our study, which is similar to findings in other health fields. Study limitations include lack of unanimous agreement about TTO's validity in measuring utility values, and MTurk participant reports can be generalized to greater population.

CONCLUSION

NBD is perceived by the community as having a substantial impact on the lives of children with spina bifida, representing a 16% reduction from perfect health. In general, health state utilities have been increasingly used in healthcare systems to understand how burdensome a population perceives a disease is and to evaluate whether interventions improve quality of life years.

Small intestinal bacterial overgrowth in spinal cord injury patients

AIM

Spinal cord injury (SCI) patients may have intestinal dysmotility and digestive symptoms that are associated with small intestinal bacterial overgrowth (SIBO). The aim of this study is to describe the prevalence of SIBO in SCI patients and the risk factors of its development.

METHODS

Twenty-nine consecutive SCI patients were studied (10 women/19 men; mean age 47 years), 16 with subacute injuries (<9 months) and 13 with chronic injuries (>1 year). Nine patients were affected by tetraplegia and 15 by paraplegia. Each patient underwent a glucose breath test according to the North American Consensus and the presence of abdominal symptoms was evaluated during the test. The results were compared with 15 non-neurological patients with SIBO.

RESULTS

Six patients tested positive for SIBO (21%), all of them affected by SCI in the subacute phase, 6/16 vs. 0/13 in the chronic phase (P<.05) and the majority with tetraplegia, 5/9 vs. 1/19 with paraplegia (P<.05). No statistically significant relationship was found with other clinical characteristics. All the tests were positive for methane or mixed (methane and hydrogen), while only 67% of the controls had methane-predominant production (P>.05).

CONCLUSION

SCI patients can develop SIBO, more frequently in the subacute phase and in tetraplegic patients, highlighting a high production of methane. This complication should be considered in neurogenic bowel management.

Functional Constipation and the Gut Microbiome in Children: Preclinical and Clinical Evidence

Functional constipation is a common condition in childhood with significant impact on patients' quality of life and on health care resources. Functional constipation is characterized by decreased bowel movements and/or hard stools, which cause significant distress for children and their caregivers. While the term "functional" may imply the absence of organic causes with a focus on behavioral aspects, 40% of children continue to have symptoms beyond conventional management with one in four children continuing to experience constipation into adulthood. The refractory and chronic nature of constipation highlights the importance of considering a range of pathophysiological mechanisms, including the potential role of the gut microbiome. In this review, we provide an overview of preclinical and clinical studies that focus on the potential mechanisms through which the gut microbiome might contribute to the clinical presentation of functional constipation in pediatrics.

Who is managing the bowels? A survey of clinical practice patterns in spina bifida clinics

PURPOSE

Neurogenic bowel dysfunction (NBD) affects 80% of individuals with spina bifida. Performing and disseminating research on NBD to reach the appropriate audience is difficult given the variability among medical specialties managing NBD. This study aimed to identify which medical specialties and types of providers are currently managing NBD in the United States.

METHODS

A survey was developed and sent to 75 spina bifida clinics. Surveys queried which specialty was primarily responsible for medical and surgical management of NBD and any others that assist in NBD care. The license and certification level of the providers were collected. Descriptive statistics were performed to describe the results.

RESULTS

Response rate was 68%. Urology was the leading specialty primarily responsible for NBD management (39%) followed by rehabilitation medicine and developmental pediatrics (22% and 20%, respectively). Physicians were the primary providers of care followed by nurse practitioners (54% vs 31%). Urology performs 65% of NBD surgeries.

CONCLUSION

Multiple specialties and providers are involved in NBD management with variation among clinics. Development of improved NBD care should include a spectrum of specialties and providers. Dissemination of research should be aimed at multiple specialty groups.

Bowel function and care: Guidelines for the care of people with spina bifida

PURPOSE

Bowel dysfunction, such as constipation and fecal incontinence, has a significant impact on health, activities of daily living, and quality of life among people with spina bifida. Secondary complications may result from bowel dysfunction and include urologic dysfunction, loss of skin integrity, shunt (hydrocephalus) function, as well as loss of social opportunities and employability.

METHODS

Using a consensus building methodology, the guidelines for management of bowel dysfunction in spina bifida were written by experts in the field of spina bifida and bowel function and care.

RESULTS

The evidence-based guidelines are presented in table format and provide age-specific recommendations to achieve fecal continence without constipation. Recommended treatments are presented from least to most invasive options. Literature supporting the recommendations and the interval research published to date is also presented.

CONCLUSION

These guidelines present a standardized approach to management of bowel dysfunction in spina bifida. Bowel management in children and young adults with spina bifida is limited by variability in clinical practice and paucity of robust research in neurogenic bowel. Collaborative multi-institutional efforts are needed to overcome research barriers and provide innovative solutions.

Small Intestinal Bacterial Overgrowth in Children: A State-Of-The-Art Review

Small intestinal bacterial overgrowth (SIBO) is a heterogenous and poorly understood entity characterised by an excessive growth of select microorganisms within the small intestine. This excessive bacterial biomass, in turn, disrupts host physiology in a myriad of ways, leading to gastrointestinal and non-gastrointestinal symptoms and complications. SIBO is a common cause of non-specific gastrointestinal symptoms in children, such as chronic abdominal pain, abdominal distention, diarrhoea, and flatulence, amongst others. In addition, it has recently been implicated in the pathophysiology of stunting, a disease that affects millions of children worldwide. Risk factors such as acid-suppressive therapies, alterations in gastrointestinal motility and anatomy, as well as impoverished conditions, have been shown to predispose children to SIBO. SIBO can be diagnosed via culture-dependant or culture-independent approaches. SIBO's epidemiology is limited due to the lack of uniformity and consensus of its diagnostic criteria, as well as the paucity of literature available. Antibiotics remain the first-line treatment option for SIBO, although emerging modalities such as probiotics and diet manipulation could also have a role. Herein, we present a state-of-the-art-review which aims to comprehensively outline the most current information on SIBO in children, with particular emphasis on the gut microbiota.

Malone Antegrade Continence Enemas vs. Cecostomy vs. Transanal Irrigation-What Is New and How Do We Counsel Our Patients?

PURPOSE OF REVIEW

No gold standard exists for managing neurogenic bowel dysfunction, specifically in individuals with spina bifida. Since the International Children's Continence Society published its consensus document on neurogenic bowel treatment in 2012, an increased focus on why we must manage bowels and how to improve our management has occurred. This review provides updated information for clinicians.

RECENT FINDINGS

A surge in research, mostly retrospective, has been conducted on the success and satisfaction of three types of management for neurogenic bowel. All three management techniques have relatively high success rates for fecal continence and satisfaction rates. Selection of which treatment to carry out still is debated among clinicians. Transanal irrigation is a safe and effective management option for neurogenic bowel that does not require surgery. Antegrade enemas can be carried out via cecostomy tube or Malone antegrade continence enema with similar fecal continence outcomes.

Is It Useful to Administer Probiotics Together With Proton Pump Inhibitors in Children With Gastroesophageal Reflux?

Background/Aims

Gastroesophageal reflux disease (GERD) is a frequent condition diagnosed in children and treated with proton pump inhibitors (PPI). Long-term PPI administration can alter intestinal bacterial population by suppressing the gastric acid barrier and may cause diarrhea. The aim of this study is to evaluate the prevalence of small intestinal bacterial overgrowth assessed by glucose hydrogen breath test among children that received 12 weeks of PPI with or without probiotics (Lactobacillus reuteri DSM 17938) associated, compared to controls.

Methods

Glucose hydrogen breath test was performed before PPI treatment and after 12 weeks of PPI treatment to 128 consecutive children with GERD (1–18 years old) and a control group (120 healthy children). The children with GERD were randomized into 2 groups: placebo group (64 who received PPI and placebo for 12 weeks) and probiotics group (64 who received PPI and probiotics for 12 weeks).

Results

After 12 weeks of treatment, dysbiosis was detected among 56.2% of children from placebo group (36/64), compared to 6.2% of children from the probiotics group (4/64, P < 0.001). Bacterial overgrowth was detected in 5% of controls (6/120). Probiotics group had a lower prevalence of dysbiosis, similar to controls (P = 0.740).

Conclusion

Probiotics administration decreased the rate of dysbiosis among children treated with PPI.

Diagnosis and treatment of small intestinal bacterial overgrowth

A huge number of bacteria are hosted in the gastrointestinal tract, following a gradient increasing towards the colon. Gastric acid secretion and intestinal clearance provide the qualitative and quantitative partitioning of intestinal bacteria; small intestinal bacteria overgrowth (SIBO) occurs when these barrier mechanisms fail. Diagnosis of SIBO is challenging due to the low specificity of symptoms, the frequent association with other diseases of the gastrointestinal tract and the absence of optimal objective diagnostic tests. The therapeutic approach to SIBO is oriented towards resolving predisposing conditions, and is supported by antibiotic treatment to restore the normal small intestinal microflora and by modifications of dietary habits for symptomatic relief. In the near future, metagenomics and metabolomics will help to overcome the uncertainties of SIBO diagnosis and the pitfalls of therapeutic management, allowing the design of a personalized strategy based on the direct insight into the small intestinal microbial community.

The effects of connective tissue manipulation and Kinesio Taping on chronic constipation in children with cerebral palsy: a randomized controlled trial

PURPOSE

The aim of this study was to investigate the effects of connective tissue manipulation (CTM) and Kinesio Taping^® (KT) on constipation and quality of life in children with cerebral palsy (CP).

METHOD

This study was designed as a randomized controlled trial. Forty children diagnosed with chronic constipation based on Rome III criteria were randomly assigned to CTM group [6 females, 7 males; 8 y 6 mo (SD = 3y 4 mo)], KT group [7 female, 7 male; 8y 7 mo (SD =3y 5 mo)] or control group [6 female, 7 male; 8y 3 mo (SD = 3y 6 mo)]. All patients were assessed with 7-day bowel diaries, Bristol Stool Form Scale (BSFS), Visual Analog Scale (VAS), and Pediatric Quality of Life Inventory (PEDsQL). Kruskal-Wallis, Wilcoxon's signed-rank, and Mann-Whitney U tests were used to determine intra-group and inter-group differences. The level of significance was p < 0.05.

RESULTS

Among the CTM, KT, and control groups, there were statistically significant differences regarding the changes in defecation frequency (2.46, 3.00, 0.30, ES 1.16, p < 0.001), duration of defecation (5.07, 5.35, 0.15, ES 2.37, p = 0.003), BSFS (1.84, 2.14, 0.07, ES 0.91, p < 0.001), VAS (4.83, 3.87, 0.23, ES 1.98, p < 0.001), and PEDsQL total scores (7, 14, 8.36, -0.85, ES 4.08, p < 0.001).

CONCLUSIONS

This study revealed that CTM and KT seem equally effective physiotherapy approaches for the treatment of pediatric constipation and these approaches may be added to bowel rehabilitation program. Implications for rehabilitation CTM and KT have similar effectiveness in alleviating the constipation-related symptoms and improving quality of life in children with CP. CTM and KT can be integrated into bowel rehabilitation programs. Considering the characteristics of patients, these treatment options can be used as an alternative of each other by physiotherapists.

Upper gastrointestinal dysmotility and small intestinal bacterial overgrowth in patients with functional constipation

AIM

To explore the association between upper and lower gastrointestinal (GI) motility, as well as that between small intestinal bacterial overgrowth (SIBO) and abdominal symptoms in patients with functional constipation (FC).

METHODS

Consecutive patients with FC who met Rome III criteria were enrolled. The symptoms of constipation were assessed by the patient assessment of constipation symptom (PAC-SYM) questionnaire. All subjects underwent lactulose hydrogen breath test (LHBT) and colonic transit test. The association between delayed colonic transit time (CTT) and delayed orocecal transit time (OCTT), as well as that between delayed OCTT and SIBO were investigated. Abdominal symptom scores were compared between the SIBO positive and negative groups.

RESULTS

Forty-five patients were enrolled. Twenty-five patients had delayed CTT and 19 had delayed OCTT. The SIBO positive rate in FC patients was 44.4%. The frequency of delayed OCTT was significantly higher in the delayed CTT group than in the normal CTT group (P = 0.036). The delayed OCTT group rated more occurrence of SIBO (P < 0.001). There was a significant difference in bloating symptom score between the SIBO positive and negative groups (P = 0.043).

CONCLUSION

FC patients may also have upper GI dysmotility. SIBO may be associated with delayed OCTT and may aggravate the bloating symptom in FC patients.

Small Bowel Bacterial Overgrowth in Children

OBJECTIVES

The aim of study was to perform a comprehensive review of the pathogenesis, available diagnostic procedures, prevalence, clinical manifestations, and consequences of small bowel bacterial overgrowth (SBBO) as well as treatment options in the pediatric population.

METHODS

A literature search including MEDLINE, PubMed, and Web of Science databases was performed.

RESULTS

SBBO is found in a variety of childhood conditions in which the normal homeostatic mechanisms restricting bacterial colonization in the small bowel are disturbed by congenital or acquired anatomical abnormalities, diminished gastric acid secretion, congenital alteration of intestinal motility or acquired small bowel diseases, or other chronic disorders including primary or acquired immunodeficiency. Data show that SBBO may be an underrecognized cause of pediatric morbidity. Although several diagnostic tests for SBBO determination are available, each has its drawbacks and limitations. Indeed, there is still no "criterion standard" for SBBO diagnosis in the pediatric population. Owing to lack of established guidelines and few published interventional studies that assess the effectiveness of SBBO therapy, treatment of children with SBBO remains empiric and comprises antibiotic or probiotic therapy.

CONCLUSIONS

Further research is needed to determine the clinical impact of SBBO and to establish diagnostic and therapeutic guidelines applicable to children.

Modern Guidelines for Bowel Preparation and Antimicrobial Prophylaxis for Open and Laparoscopic Urologic Surgery

Mechanical bowel preparation (MBP) and antibiotics (oral and/or intravenous) have historically been used to decrease infectious complications in surgeries that involve manipulation of bowel or potential risk of injury. The use of MBP has recently been challenged in the colorectal surgery literature, thus inspiring similar critical evaluation of our practices in urology. This review gives a brief overview of the history of mechanical and oral antibiotic bowel preparation, as well as the evolution of the practice trends in colorectal surgery and urology. We also examine contemporary guidelines in skin preparation as well as antimicrobial prophylaxis before surgery.

The role of methane in mammalian physiology-is it a gasotransmitter?

Mammalian methanogenesis is widely considered to be an exclusive sign of anaerobic microbial activity in the gastrointestinal tract. This commonly held view was challenged, however, when in vitro and in vivo investigations demonstrated the possibility of nonmicrobial methane formation in aerobic organisms, in plants and animals. The aim of this review is to discuss the available literature data on the biological role of methane. When we evaluate the significance of methane generation in the mammalian physiology, the question may be examined: is it a gas mediator? Overall the data do not fully support the gasotransmitter concept, but they do support the notion that methane liberation may be linked to redox regulation and may be connected with hypoxic events leading to, or associated with a mitochondrial dysfunction. In this respect, the available information suggests that hypoxia-induced methane generation may be a necessary phenomenon of aerobic life, and perhaps a surviving evolutionary trait in the eukaryote cell.