Machine learning-based prediction models affecting the recovery of postoperative bowel function for patients undergoing colorectal surgeries.

PURPOSE: The debate surrounding factors influencing postoperative flatus and defecation in patients undergoing colorectal resection prompted this study. Our objective was to identify independent risk factors and develop prediction models for postoperative bowel function in patients undergoing colorectal surgeries. METHODS: A retrospective analysis of medical records was conducted for patients who undergoing colorectal surgeries at Peking University People's Hospital from January 2015 to October 2021. Machine learning algorithms were employed to identify risk factors and construct prediction models for the time of the first postoperative flatus and defecation. The prediction models were evaluated using sensitivity, specificity, the Youden index, and the area under the receiver operating characteristic curve (AUC) through logistic regression, random forest, Naïve Bayes, and extreme gradient boosting algorithms. RESULTS: The study included 1358 patients for postoperative flatus timing analysis and 1430 patients for postoperative defecation timing analysis between January 2015 and December 2020 as part of the training phase. Additionally, a validation set comprised 200 patients who undergoing colorectal surgeries from January to October 2021. The logistic regression prediction model exhibited the highest AUC (0.78) for predicting the timing of the first postoperative flatus. Identified independent risk factors influencing the time of first postoperative flatus were Age (p < 0.01), oral laxatives for bowel preparation (p = 0.01), probiotics (p = 0.02), oral antibiotics for bowel preparation (p = 0.02), duration of operation (p = 0.02), postoperative fortified antibiotics (p = 0.02), and time of first postoperative feeding (p < 0.01). Furthermore, logistic regression achieved an AUC of 0.72 for predicting the time of first postoperative defecation, with age (p < 0.01), oral antibiotics for bowel preparation (p = 0.01), probiotics (p = 0.01), and time of first postoperative feeding (p < 0.01) identified as independent risk factors. CONCLUSIONS: The study suggests that he use of probiotics and early recovery of diet may enhance the recovery of bowel function in patients undergoing colorectal surgeries. Among the various analytical methods used, logistic regression emerged as the most effective approach for predicting the timing of the first postoperative flatus and defecation in this patient population.

Deciphering the Impact of Defecation Frequency on Gut Microbiome Composition and Diversity.

This study explores the impact of defecation frequency on the gut microbiome structure by analyzing fecal samples from individuals categorized by defecation frequency: infrequent (1-3 times/week, n = 4), mid-frequent (4-6 times/week, n = 7), and frequent (daily, n = 9). Utilizing 16S rRNA gene-based sequencing and LC-MS/MS metabolome profiling, significant differences in microbial diversity and community structures among the groups were observed. The infrequent group showed higher microbial diversity, with community structures significantly varying with defecation frequency, a pattern consistent across all sampling time points. The Ruminococcus genus was predominant in the infrequent group, but decreased with more frequent defecation, while the Bacteroides genus was more common in the frequent group, decreasing as defecation frequency lessened. The infrequent group demonstrated enriched biosynthesis genes for aromatic amino acids and branched-chain amino acids (BCAAs), in contrast to the frequent group, which had a higher prevalence of genes for BCAA catabolism. Metabolome analysis revealed higher levels of metabolites derived from aromatic amino acids and BCAA metabolism in the infrequent group, and lower levels of BCAA-derived metabolites in the frequent group, consistent with their predicted metagenomic functions. These findings underscore the importance of considering stool consistency/frequency in understanding the factors influencing the gut microbiome.

Anorectal function and symptoms 6 months after robot-assisted laparoscopic radical prostatectomy: a single-center study.

INTRODUCTION: Robot-assisted laparoscopic radical prostatectomy (RALP) is a common procedure for the treatment of localised prostate cancer. Anorectal symptoms such as fecal incontinence (FI), rectal urgency or disturbed defecation have been reported after the operation. Anorectal function is dependent on the integrity of anal and pelvic nerves and muscles, rectal sensory function as well as rectal reservoir function. The aim of this study was to investigate the potential influence of RALP on anorectal physiological function and bowel symptoms. MATERIALS AND METHODS: In this pilot study, 29 patients with localised prostate cancer scheduled for RALP were included. Anorectal physiology was used to measure rectal sensitivity and reservoir function as well as anal sphincter pressures. Bowel symptoms were measured by a bowel function questionnaire and a 2-week bowel function diary. Measurements were done before the operation and repeated at 6 months after the operation. RESULTS: The study observed a significant postoperative increase in rectal sensory threshold for rectal balloon distention, from 20 to 40 mmHg, P < 0.001. This change is indicative of a decrease in rectal sensation after RALP. There were no other statistical significant differences in any of the physiological tests performed. Importantly, there was no change in any of the bowel symptoms after surgery. CONCLUSION: This study showed that RALP may lead to impaired rectal sensory function. This finding did not, however, seem to have any influence on the patients´ postoperative clinical bowel function.

Functional Constipation and Obstructed Defecation.

Constipation encompasses symptoms of decreased colonic motility or difficulty with the defecation process. As a broad definition, this can be inclusive of functional constipation (FC) or colonic inertia, obstructed defecation (OD), and irritable bowel syndrome-constipation type (IBS-CS). After excluding IBS-C, FC and OD diagnosis and management require a multidisciplinary approach often involving nutritionists, pelvic floor therapists, urogynecologists, and colon and rectal surgeons. Differentiating the presence or absence of each can direct therapy and prognosticate chances for improvement in this often complex combination of disorders.

Psyllium husk powder increases defecation frequency and faecal score, bulk and moisture in healthy cats.

OBJECTIVES: Constipation is the infrequent or difficult emission of hard, dry faeces and is a common digestive condition in cats. Psyllium is a low-fermentable fibre, with soluble and insoluble components and water-holding properties. It forms a mucilaginous gel with water and is used for the symptomatic treatment of constipation in various species. This study evaluated the effect of dietary psyllium on faecal characteristics in cats. METHODS: Healthy neutered adult cats (six female and three male, aged 3.3-4.4 years) were consecutively fed a dry extruded diet containing either 6% psyllium (test) or 6% cellulose (control) for 10 days each. During the last 3 days (the collection days) of both feeding periods, bowel movements and faecal scores were recorded, and faeces were collected to measure wet weight and moisture. The statistical analysis used linear mixed models with diet, day and their interaction as fixed effects and animal as a random term. RESULTS: The test diet was associated with significantly more bowel movements per day over 3 days (P = 0.0052) and on collection day 2 (P = 0.0229) than the control diet. The mean faecal score was higher (softer faeces) over all three collection days (P <0.0001) and on collection days 1, 2 and 3 (P = 0.0011, P = 0.0349, P = 0.0003, respectively) for the test diet vs the control diet; the total faecal wet weight (P = 0.0003) and faecal moisture (%) were also higher (P = 0.0426) for the test diet. Faeces associated with the test diet often had a dry shell and soft interior, which increased the faecal score. CONCLUSIONS AND RELEVANCE: Psyllium promoted more bowel movements and higher faecal moisture and faecal score in healthy cats, consistent with a previous uncontrolled clinical trial in constipated cats. Together, the studies support the use of dietary psyllium for managing cats with constipation.

Correlation between Pain and Anal Defecation Function in Postoperative Patients with Colorectal Cancer and Related Factors Affecting Patients' Prognosis.

BACKGROUND: The degree of postoperative pain and defecation function in colorectal cancer will affect patients' prognosis. Therefore, exploring the correlation between postoperative pain and defecation function, and analyzing the related factors, will help to improve the quality of patients' prognosis. METHODS: A total of 94 patients with colorectal cancer admitted to our hospital from March 2022 to June 2023 were retrospectively selected for study. The visual analog scale (VAS) was used to evaluate the pain level of the patients. The low anterior resection syndrome (LARS) scale was used to evaluate bowel function of the patients, and the incidence of LARS was recorded. The patients were grouped according to whether or not they had the complications of LARS, and they were divided into the groups of concurrent LARS and non-concurrent LARS. The patients' anorectal pressure was measured, and the measurements included maximum tolerated volume (MTV), anorectal resting pressure (ARP), and maximum squeeze pressure (MSP). Pearson's correlation coefficient was used to test associations between anal defecation function and postoperative pain and anorectal manometry. Logistic regression was used to test predictors of concurrent LARS, and the value of each of the indices for prediction of LARS was examined using the receiver operating characteristic (ROC). RESULTS: Patients' VAS scores were positively correlated with LARS scores (p < 0.05). A total of 22 patients with VAS score ≥20 points were found to have a LARS incidence of 23.40% based on the LARS score. The VAS score was higher in the concurrent LARS group than in the non-concurrent LARS group (p < 0.05). The concurrent LARS group had a higher percentage of patients with age ≥60 years, body mass index ≥24 kg/m2, anastomotic position <5 cm from the anal verge, preoperative radiotherapy, and anastomotic fistula than the non-current LARS group (p < 0.05). The levels of MTV, ARP, and MSP were lower in patients in the concurrent LARS group than in the non-current LARS group (p < 0.05). Patients' LARS scores were negatively correlated with MTV (r = -0.420), ARP (r = -0.300) and MSP (r = -0.220) levels (p < 0.05). Logistic regression analysis showed that anastomotic position <5 cm from the anal verge, preoperative radiotherapy, anastomotic fistula, high VAS level, and low MTV level were all significant predictors of concurrent LARS. Anastomotic position, whether or not radiotherapy was administered preoperatively, anastomotic fistula, VAS score, and MSP level all had high sensitivity and specificity for prediction of concurrent LARS, and the combined area under the curve (AUC) of each index was 0.921, sensitivity was 0.818, and specificity was 0.944. CONCLUSION: LARS is strongly associated with the patient's pain level, and factors such as anastomotic position <5 cm from the anal verge, preoperative radiotherapy, anastomotic fistula, high VAS level, and low MTV level will increase the risk of concurrent LARS in patients.

Correlation between congenital pelvic floor muscle development assessed by magnetic resonance imaging and postoperative defecation.

OBJECTIVE: Children with congenital anorectal malformation (CAM) experience challenges with defecation. This study aims to assess defecation in preschool-age children with CAM and to evaluate the correlation between pelvic floor muscle developed assessed by magnetic resonance imaging (MRI) and postoperative defecation. METHODS: We collected clinical data and MRI results from 89 male children with CAM. The bowel function scores for children with Perineal (cutaneous) fistula, Rectourethral fistula(Prostatic or Bulbar), and Rectovesical fistula were computed. MRI scans were subjected to image analysis of the striated muscle complex (SMC). The association between pelvic floor muscle score and bowel function score was examined using the Cochran-Armitage Trend Test. RESULTS: We observed that 77.4% of the SMC scores by MRI for Perineal fistula were good. The Rectourethral fistula SMC score was 40.6% for moderate and 59.4% for poor. The SMC score for Rectovesical fistula was 100% for moderate. Furthermore, 77.4% of patients with Perineal fistula had bowel function scores (BFS) ≥ 17 points. Among those with Rectourethral fistula and Rectovesical fistula, 12.5% and 0 had BFS ≥ 17 points, respectively. An analysis of muscle development and bowel function in patients with Rectovesical fistula, Rectourethral fistula, and Perineal fistula revealed a correlation between SMC development and BFS. Subgroup analysis showed that the Perineal fistula had statistical significance; however, the Rectourethral fistula and Rectovesical fistula were not statistically significant. CONCLUSION: A correlation exists between pelvic floor muscle development and postoperative defecation in children with Perineal fistula.

Effect of prebiotic oligosaccharides on bowel habit and the gut microbiota in children with functional constipation (Inside study): study protocol for a randomised, placebo-controlled, multi-centre trial.

BACKGROUND: Functional constipation (FC) in children is a common gastrointestinal disorder with a worldwide-pooled prevalence of 9.5%. Complaints include infrequent bowel movements, painful defecation due to hard and/or large stools, faecal incontinence, and abdominal pain. Prebiotic oligosaccharides have been shown to relieve constipation symptoms in young adults and elderly. However, sufficient evidence is lacking linking additional prebiotic intake to improve symptoms in children with FC. We hypothesise that prebiotic oligosaccharides are able to relieve symptoms of constipation in young children as well. METHODS: In the present randomised, double-blind, placebo-controlled, multi-centre study, we will study the effects of two prebiotic oligosaccharides in comparison to placebo on constipation symptoms in children of 1-5 years (12 to 72 months) of age diagnosed with FC according to the Rome IV criteria for functional gastrointestinal disorders. The primary outcome measure will be change in stool consistency. Secondary outcomes include stool frequency and stool consistency in a number of cases (%). Tertiary outcomes include among others painful defecation, use of rescue medication, and quality of life. In addition, the impact on gut microbiome outcomes such as faecal microbiota composition and metabolites will be investigated. Participants start with a run-in period, after which they will receive supplements delivered in tins with scoops for 8 weeks, containing one of the two prebiotic oligosaccharides or placebo, followed by a 4-week wash-out period. DISCUSSION: This randomised double-blind, placebo-controlled multi-centre study will investigate the effectiveness of prebiotic oligosaccharides in children aged 1-5 years with FC. TRIAL REGISTRATION: ClinicalTrials.gov NCT04282551. Registered on 24 February 2020.

Priorities, needs and willingness of use of nerve stimulation devices for bladder and bowel function in people with spinal cord injury (SCI): an Australian survey.

STUDY DESIGN: Anonymous online survey OBJECTIVES: To investigate the priorities, needs and willingness to adopt nerve stimulation devices for managing neurogenic bladder and bowel function in people with spinal cord injury (SCI) living in Australia. SETTING: Online survey of people living with SCI in Australia. METHODS: This anonymous online survey used Qualtrics and was advertised via standard communication channels, such as advocacy groups representing the SCI community in Australia, social media, attending SCI sporting events and by word-of-mouth. RESULTS: Responses from 62 individuals (32% female, 68% male) were included. Bladder emptying through urethra without catheter was the highest priority for bladder function. Reducing time required for bowel routines and constipation were the top priorities regarding bowel function. The highest concern for internal/implanted devices was the 4% chance of device surgical removal, while wearing wires under the clothes was the main concern for external devices. 53% of respondents were willing to trial an implanted nerve stimulation device, while 70% would trial an external device to improve and gain independence in bladder and bowel function. CONCLUSION: The findings of this study highlighted the potential role in which nerve stimulation can have in addressing bladder and bowel dysfunction in people with SCI, and have also identified that there was a need for Australian physiotherapists to evaluate their role in bladder and bowel dysfunction. Results from this study can help guide further research in nerve stimulation devices for bladder and bowel dysfunction in people with SCI. SPONSORSHIP: n/a.

Relationship of Age and Gender to Motility Test Results and Symptoms in Patients with Chronic Constipation.

BACKGROUND/AIMS: Patients with chronic constipation (CC) exhibit symptoms and functional abnormalities upon testing, but their relationship to age and gender is unclear. We assessed age- and gender-related differences in symptoms, colon transit time, and anorectal motility, sensation, and expulsion. PATIENTS AND METHODS: Retrospective, post hoc data analysis of patients with CC, who underwent Wireless Motility Capsule (WMC), High-Resolution Anorectal Manometry (HR-ARM), Balloon Expulsion Test (BET) and Rectal Sensory Testing (RST). Clinical assessment was made by questionnaires. Standard WMC criteria for colonic transit time (CTT) and the London classification was used for HR-ARM analyses, and regression plots between age, gender, CTT, HR-HRM, RST and BET were calculated. RESULTS: We studied 75 women and 91 men. Abdominal pain, infrequent defecation, incomplete evacuation, defecatory straining, and multiple motility and anorectal function abnormalities were common. Abdominal pain was least frequently, and straining was most frequently associated with a motility abnormality. For each symptom, the highest prevalence was associated with failed BET. There was a significant increase in CTT with age only in men (p = 0.0006). In men, for each year of age there was a CTT increase of 1.02 h. The prevalence of abdominal pain and incomplete evacuation for females was significantly higher than that for males (both P < 0.05). The prevalence of low anal squeeze pressure for females was significantly higher than that for males, and the prevalence of poor rectal sensation for males was significantly higher than that for females (both P < 0.05). A significant decrease in basal anal and squeeze pressures with age occurred in women (p < 0.0001); an increase in age of one year was associated with a decrease in anal base pressure of 1.2 mmHg. Abnormal CTT and HR-ARM tests were associated with increased symptom frequency, but not severity. CONCLUSIONS: There are significant age- and gender-related differences in symptoms, CTT, and HR-HRM parameters, rectal sensation, and expulsion, that may influence the multifaceted management of constipation.

Does a Preoperative Bowel Regimen Change Time to Bowel Movement? A Randomized Clinical Trial.

IMPORTANCE: This study is important because it aimed to assess an intervention to decrease patient discomfort after a robotic sacral colpopexy. OBJECTIVE: Our primary outcome was to determine whether preoperative use of polyethylene glycol decreases time to first bowel movement postoperatively. Secondary outcomes include degree of pain with first bowel movement and stool consistency. STUDY DESIGN: This was a randomized controlled trial. The experimental group was assigned polyethylene glycol daily for 7 days before surgery and the control group was not. All patients received polyethylene glycol postoperatively. RESULTS: There was no statistically significant reduction in the time to first postoperative bowel movement when preoperative polyethylene glycol was used (mean [SD] in days for the control and experimental groups of 2.32 [0.99] and 1.96 [1.00], P = 0.21). There was a statistically significant reduction in pain levels with the first postoperative bowel movement in the experimental group (median [IQR] of 4 [2-5] vs 1 [0-2], P = 0.0007). Postoperative day 1 pain levels were also significantly lower in the experimental group (median [IQR] of 4 [3-6] vs 2 [0-4], P = 0.0484). In addition, patients had decreased average postoperative pain levels over 7 days with an estimated difference in the median pain levels of 1.88 units (95% confidence interval, 0.64-3.12; P = 0.0038). CONCLUSIONS: Preoperative administration of polyethylene glycol did not decrease time to first postoperative bowel movement. Patients in the experimental group exhibited less pain with their first postoperative bowel movement and had improved pain levels on postoperative day 1.

Functional Disorders of the Ileal-Anal Pouch: A Systematic Review.

BACKGROUND: The IPAA is a boon to patients needing proctocolectomy but maintains per anal function through anatomic and physiologic compromises. The state of pouch function is hard to define because pouch anatomy is not normal and pouch physiology is a distortion of normal defecation. Patients with pouches develop multiple symptoms: some are expected, some are disease related, and some are the result of surgical complications. It is important to understand the cause of pouch-related symptoms so that appropriate management is offered. OBJECTIVES: The study aimed to review pouch symptoms and discuss their likely cause, review the literature on pouch function and dysfunction, and provide clarity to clear the confusion. DATA SOURCES: PubMed and Cochrane databases were searched using the terms "ileoanal pouch function" and "ileoanal pouch dysfunction." STUDY SELECTION: From 1983 to 2023, 553 articles related to "ileoanal pouch function" and 178 related to "ileoanal pouch dysfunction" were reviewed. Nine studies appeared under both headings. Case studies, duplicate publications, and articles concerning pouch diseases were excluded. MAIN OUTCOME MEASURES: Definitions of pouch function and dysfunction, methods of describing and scoring symptoms, and understanding of expected changes in pouch function given the nature of the surgery. RESULTS: Twenty-seven studies were reviewed from the ileoanal pouch dysfunction search and 38 from ileoanal pouch function. Three studies tried to define normal pouch function, 10 attempted to measure pouch function, and 4 aimed to score pouch function. Only 3 studies addressed pouch physiology. LIMITATIONS: A full discussion of pouch dysfunction is limited by the lack of studies focussing on the anatomic and physiologic consequences of turning the terminal ileum into an organ of storage. CONCLUSIONS: Most studies of pouch function and dysfunction do not consider expected changes in the physiology of defecation that follow restorative proctocolectomy. Thus, most studies of pouch function produce conclusions that lack an important dimension. See video from symposium.

Randomized controlled trial of linaclotide in children aged 6-17 years with functional constipation.

OBJECTIVES: Linaclotide, a guanylate cyclase-C agonist, was recently approved in the United States for treatment of children 6-17 years old with functional constipation (FC). This study evaluated the safety and efficacy of several linaclotide doses in children 6-17 years old with FC. METHODS: In this multicenter, randomized, double-blind, placebo-controlled phase 2 study, 173 children with FC (based on Rome III criteria) were randomized to once-daily linaclotide (A: 9 or 18 µg, B: 18 or 36 µg, or C: 36 or 72 µg) or placebo in a 1:1:1:1 ratio for 6- to 11-year-olds (dosage determined by weight: 18 to <35 or ≥35 kg) and linaclotide (18, 36, 72, or 145 µg) or placebo in a 1:1:1:1:1 ratio for 12- to 17-year-olds. The primary efficacy endpoint was change from baseline in weekly spontaneous bowel movement (SBM) frequency throughout the 4-week treatment period. Adverse events (AE), clinical laboratory values, and electrocardiograms were monitored. RESULTS: Efficacy and safety were assessed in 173 patients (52.0% aged 6-11 years; 48.0% aged 12-17 years); 162 (93.6%) completed the treatment period. A numerical improvement in mean SBM frequency was observed with increasing linaclotide doses (1.90 in 6- to 11-year-olds [36 or 72 µg] and 2.86 in 12- to 17-year-olds [72 µg]). The most reported treatment-emergent AE was diarrhea, with most cases being mild; none were severe. CONCLUSIONS: Linaclotide was well tolerated in this pediatric population, with a trend toward efficacy in the higher doses, warranting further evaluation.

Postoperative outcomes of transperitoneal versus retroperitoneal robotic partial nephrectomy: a propensity-score matched comparison focused on patient mobilization, return to bowel function, and pain.

Literature meta-analyses comparing transperitoneal versus retroperitoneal approach to robotic partial nephrectomy (RPN) suggested some advantages favoring retroperitoneoscopy. Unfortunately, patient-centered data about mobilization, canalization, pain, and use of painkillers remained anecdotally reported. The present analysis aimed to compare transperitoneal versus retroperitoneal RPN focusing on such outcomes. Study data including baseline variables, perioperative, and postoperative outcomes of interest were retrieved from prospectively maintained institutional database (Jan 2018-May 2023) and compared between treatment groups (transperitoneal versus retroperitoneal). Propensity score matching was performed using the STATA command psmatch2 considering age, sex, body mass index, previous abdominal surgery, RENAL score, tumor size and location, and cT stage. The logit of propensity score was used for matching, with a 1:1 nearest neighbor algorithm, without replacement (caliper of 0.001). A total of 442 patients were included in the unmatched analysis: 330 underwent transperitoneal RPN 112 retroperitoneal RPN. After propensity score, 98 patients who underwent retroperitoneal RPN were matched with 98 patients who underwent transperitoneal RPN. Matched cohorts had comparable patients' demographics and tumor features. We found similarity between the two laparoscopic accesses in all outcomes but in blood loss, which favored retroperitoneoscopic RPN (median 150 (IQR 100-300) versus 100 (IQR 0-100) ml, p = 0.03). No differences were found in terms of time to mobilization with ambulation, return to complete bowel function, postoperative pain, but higher painkillers consumption was reported after transperitoneal RPN (p < 0.004). The present study compared the transperitoneal versus the retroperitoneal approach to RPN, confirming the similarity between the two approaches in all perioperative outcomes. Based on our findings, the choice of the surgical approach to RPN may remain something that the surgeon decides.

The multitarget faecal immunochemical test for improving stool-based colorectal cancer screening programmes: a Dutch population-based, paired-design, intervention study.

BACKGROUND: The faecal immunochemical test (FIT) is widely employed for colorectal cancer screening. However, its sensitivity for advanced precursor lesions remains suboptimal. The multitarget FIT (mtFIT), measuring haemoglobin, calprotectin, and serpin family F member 2, has demonstrated enhanced sensitivity for advanced neoplasia, especially advanced adenomas, at equal specificity to FIT. This study aimed to prospectively validate and investigate the clinical utlitity of mtFIT versus FIT in a setting of population-based colorectal cancer screening. METHODS: Individuals aged 55-75 years and who were eligible for the Dutch national FIT-based colorectal cancer screening programme were invited to submit both a FIT and mtFIT sample collected from the same bowel movement. Positive FIT (47 µg/g haemoglobin cutoff) or mtFIT (based on decision-tree algorithm) led to a colonoscopy referral. The primary outcome was the relative detection rate of mtFIT versus FIT for all advanced neoplasia. Secondary outcomes were the relative detection rates of colorectal cancer, advanced adenoma, and advanced serrated polyps individually and the long-term effect of mtFIT-based versus FIT-based programmatic screening on colorectal cancer incidence, mortality, and cost, determined with microsimulation modelling. The study has been registered in ClinicalTrials.gov, NCT05314309, and is complete. FINDINGS: Between March 25 and Dec 7, 2022, 35 786 individuals were invited to participate in the study, of whom 15 283 (42·7%) consented, and 13 187 (86·3%) of 15 283 provided both mtFIT and FIT samples with valid results. Of the 13 187 participants, 6637 (50·3%) were male and 6550 (49·7%) were female. mtFIT showed a 9·11% (95% CI 8·62-9·61) positivity rate and 2·27% (95% CI 2·02-2·54) detection rate for advanced neoplasia, compared with a positivity rate of 4·08% (3·75-4·43) and a detection rate of 1·21% (1·03-1·41) for FIT. Detection rates of mtFIT versus FIT were 0·20% (95% CI 0·13-0·29) versus 0·17% (0·11-0·27) for colorectal cancer; 1·64% (1·43-1·87) versus 0·86% (0·72-1·04) for advanced adenoma, and 0·43% (0·33-0·56) versus 0·17% (0·11-0·26) for advanced serrated polyps. Modelling demonstrated that mtFIT-based screening could reduce colorectal cancer incidence by 21% and associated mortality by 18% compared with the current Dutch colorectal cancer screening programme, at feasible costs. Furthermore, at equal positivity rates, mtFIT outperformed FIT in terms of diagnostic yield. At an equally low positivity rate, mtFIT-based screening was predicted to further decrease colorectal cancer incidence by 5% and associated mortality by 4% compared with FIT-based screening. INTERPRETATION: The higher detection rate of mtFIT for advanced adenoma compared with FIT holds the potential to translate into additional and clinically meaningful long-term colorectal cancer incidence and associated mortality reductions in programmatic colorectal cancer screening. FUNDING: Stand Up to Cancer, Dutch Cancer Society, Dutch Digestive Foundation, and Health~Holland.

Investigation of Expanded Human Adipose-derived Stem Cell Dosage and Timing for Improved Defecation Function.

BACKGROUND/AIM: Although certain treatment options exist for intestinal incontinence, none are curative. Adipose-derived stem cells (ADSCs) have emerged as promising therapeutic agents, but most preclinical studies of their effectiveness for anal function have used autologous or allogeneic ADSCs. In this study, the effectiveness, timing of administration, and required dosage of human ADSCs were investigated for clinical application. MATERIALS AND METHODS: A 10-mm balloon catheter was used to induce anal sphincter injury in immunodeficient mice in the following experimental groups (n=4 per group): ADSC (injected ADSCs after injury), PBS (injected phosphate-buffered saline after injury), and control (uninjured). The effects of different timing (immediately after injection and 30 days following injury) and number of human ADSCs administered was compared among groups based on defecation status and pathological evaluation. RESULTS: In terms of defecation status, groups receiving ≥1×104 human ADSCs after injection showed improvement. Pathological images showed that compared to the PBS group, the thinnest part of the sphincter was thicker for animals that received ≥1×104 human ADSCs, and fibrosis of the sphincter was notable in those treated with 1×103 human ADSCs or PBS. Furthermore, defecation status was improved by administration of human ADSCs, not only immediately after injury, but also at 30 days following injury. CONCLUSION: Human ADSC administration in a mouse model of anal sphincter injury was effective. Injection of ≥1×104 human ADSCs was the amount necessary to improve defecation status, an effect detected in both the acute and chronic phases.

Assessing the defecation practices of unsheltered individuals and their contributions to microbial water quality in an arid, urban watershed.

Outdoor defecation by people experiencing homelessness is frequently perceived as a potentially large source of human fecal pollution and a significant source of health risk in urban waterbodies with recreational contact. The goal of this study was to count the number of people experiencing homelessness and quantifies their sanitation habits in an urban river corridor setting, then use this information for estimating human fecal pollutant loading on a watershed scale. Two types of census counts were conducted including periodic point-in-time counts over six years and weekly counts of encampments. While the population census varied from count-to-count, the range of population estimates in the river corridor varied from 109 to 349 individuals during the six-year span, which mirrored the weekly counts of encampments. A face-to-face survey of people experiencing homelessness assessed the sanitation habits of the unsheltered population (N = 63), including outdoor defecation frequency and containment practices. Overall, 95 % of survey respondents reported defecating outdoors; 36 % practiced outdoor defecation between 4 and 7 days/week and 27 % practiced outdoor defecation <1 day/week. Of those that did practice outdoor defecation, 75 % contained their feces in a bucket or bag, thereby limiting fecal material contributions to the river; 6.7 % reported defecating on low ground near the river that could wash off when flood waters rise during a storm event. Only a single survey respondent reported defecating directly into the river. Based on literature values for average HF183 output for an adult human, and the average rainfall in the urban watershed, the total watershed contribution of HF183 averaged 1.2 × 1010 gene copies per storm event (95 % CI: 0.9 × 1010-1.6 × 1010) along the 41 km stretch of river in this study. This human fecal loading estimate is at least two orders of magnitude less than cumulative HF183 loading from all human sources measured at the bottom of the watershed.

Collagen patch cover facilitates recovery of bowel function after laparoscopic colectomy.

BACKGROUND: Numerous factors can influence bowel movement recovery and anastomotic healing in colorectal surgery, and poor healing can lead to severe complications and increased medical expenses. Collagen patch cover (CPC) is a promising biomaterial that has been demonstrated to be safe in animal models and has been successfully applied in various surgical procedures in humans. This study. METHODS: A retrospective review of medical records from July 2020 to June 2022 was conducted to identify consecutive patients who underwent laparoscopic colectomy. Patients who received CPC at the anastomotic site were assigned to the collagen group, whereas those who did not receive CPC were assigned to the control group. RESULTS: Data from 241 patients (collagen group, 109; control group, 132) were analyzed. Relative to the control group, the collagen group exhibited a faster recovery of bowel function, including an earlier onset of first flatus (2.93 days vs. 3.43 days, p < 0.01), first defecation (3.73 days vs. 4.18 days, p = 0.01), and oral intake (4.30 days vs. 4.68 days, p = 0.04). CPC use was also associated with lower use of postoperative intravenous analgesics. The complication rates in the two groups did not differ significantly. CONCLUSIONS: CPCs can be safely and easily applied to the anastomotic site during laparoscopic colectomy, and can accelerate bowel movement recovery. Further studies on the effectiveness of CPCs in colorectal surgery involving larger sample sizes are required. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov registration number: NCT05831956 (26/04/2023).